What speaker do you passionately want to demo?

Beyond the slight curiosity of what speaker you'd "like" to demo (example: every Klipsch horn speaker), what speaker(s) would you "passionately" love to demo?  A brief explanation of "why" you like these speakers would be beneficial.

I'll start:

MBL 101 X-treme - almost a decade and reviewers still say it's amongst the best they'd ever heard.  Probably should be matched to the MBL Electronics

Living Voice Vox Olympian Horn - it's wood (maybe sounds more warm/organic), it's a horn, and it consistently gets good reviews at the Munich High End audio shows.

Muraudio SP1 - Electrostatic + cone hybrid speaker that received many rave reviews.  It's not an easy task successfully marrying the fast electrostatic to the slower cone to sound seamless.  This speaker was on my short list to purchase.

Voxativ AC-XP field coil driver - both Voxative and Pure Audio Project speaker offer the Voxativ AC-XP field coil driver as an optional upgrade, but it's an additional ~$7k (yow).  The reviews leads me to believe that this field core driver is sonically "significantly" superior above other choices.  

Mike Lavigne's Evolution Acoustics MM7 in his dedicated sound room.  The sonics of demoing speakers at storefronts or audio shows can be problematic depending on the audio chain and the room setup.  MikeL has a matured optimized setup that is sonically recognized as excellent by other serious audiophiles.  
I've been impressed with DaVore Fidelity

I heard the Super Nines of the Gibbons series at my favorite audio dealer and was shocked on the sound from the speakers.

I love my Sonus Fabers and if money wasn't a consideration I'd have them as a second set I was so impressed.  Sometimes a change is good.  I like listening to them.

I'd also like to hear a big pair of Maggies....my friend has a pair and they are different than mine.  And I view listening to music as an activity for enjoying the moment.  While I still like my main speakers they provide a much different 'presentation' that's appealing.
Sound Labs
Stennheim -yeah its wrong but so are the swiss
Dutch & Dutch
Borreson 05
ATC 150

KennyG has a nice list too!

pretty much all the ones i have been truly passionate about demoing ... have already been in my home and have been demoed... btw - that is the ONLY way to really demo and know whether they hit the mark

for me at this point, probably the only one that is on the to do list are devore o-96’s, and maybe, graham ls5/5's ...
As a long time MBL groupie (and I owned the MBL 121s), the MBL 101 X-treme were on my list.  And I actually happened upon a private demowhen visiting the USA - a dealer had them set up in a big room.They were a total gas to listen to, though I don't think they were working optimally in the room.

I did such a big speaker search not long ago, able to listen to tons of speakers on my list, that I cleaned most of them off the list.  

But...for speakers I'm dying to audition in my home:

Devore O/96.

Loved them in the show room.  But tricky speaker to get right and I want to see how they'd sound in my room.

Even more so, I'm super intrigued about the new updated "Bronze" version of the O/96!

And I would also add how auditioning the Devore Super Nines are up there for my real-world auditioning too.

Taking off from there,  I'd also love to hear the current Spendor Classic speakers, e.g. 3/1 right through to the 200. 

I'm also very intrigued by Charney speakers.
Also: Janszen electrostatic speakers.  That sealed box design fascinates me.

Aaand, the Audio Physic Avantara and others in that range.

Plus...HORN speakers. I am so bereft of true sit-down-and-listen to horn speakers.  There's no real way they would work in my room, but I've loved the character I've glimpsed at some shows or stores.

I would love to hear the Viking system that utilizes a wide-range driver fitted to a waveguide, with the Fostex 31” woofer.  
I am also interested in the AER speaker with the single driver in a quarter wave back-loaded horn cabinet.  I’ve heard a cheaper AER driver in a more modest cabinet of similar design (Charney Audio) and that system sounded terrific.

I have heard fantastic systems utilizing G.I.P. Laboratory drivers; Deja Vu Audio makes custom designs using these drivers.  But, I have not heard their drivers in their own cabinets.  The cabinets are too big and expensive to expect anyone to import them from Japan, so it remains something I’ve not heard.

i am assuming we are talking about auditions/demos of speakers we would actually want to buy and keep for the long term ...  if not well there are many i am just kinda curious just to hear without intention of ever owning...  we won't count or list those
Honestly I’ve been around quite a bit and pretty much heard it all. Not every speaker but enough to know what different designs at all price points can sound like and do. So nothing burning at the moment. I’ll just say if you have never heard mbl set up well that should be on your list. Also Ohm. For something truly unique and different.  For something compact and affordable give a listen to a pair of kef ls50 metas. 
I don’t know about passionately, but the line of Fyne speakers looks like something I would like to hear.
The F704s would fit my room nicely :)

Floorstanding Speakers Home Cinema | Music - FYNE AUDIO
Yes thanks for reminding me.  Fyne is one line I have not heard that I would like to.  Also would like to hear more Tannoy.  
I'd like to hear the Legacy V set up with the Wavelet system.  I have issues with having to use their control/preamp/DAC equipment as it ties up a big chunk of change but would give them the benefit of the doubt until I hear the system.  
Fyne speakers. I think that I would really like them because I like Tannoy.
More Fyne dealers popping up everyday. Jim Smith of Get Better Sound has been a Tannoy fan and for years and had Canterbury speakers ($30k). He would also use Joseph Audio Perspectives ($18k); what I heard when I was in his detached, state of the art music room for one of his RoomPlay Reference sessions.

BTW, anyone that can afford to do so should experience one of Jim’s sessions. It was a game changer for me. The cost is very reasonable. The main expense is getting to Cummings, GA. Make it a short vacation and also visit The Big House (Allman Brothers museum in Macon) and spend a few days in Savannah, now one of our favorite cites in the US. Sorry to go a little off topic.

Anyway Jim heard Fyne speakers and ended up replacing his Tannoys with Fyne F703 speakers ($12k) and I believe this is his new reference.

Anyone interested in an upper end Tannoy product should go out of their way to audition Fyne F700 or F1 series speakers depending on budget.
When I had the room for anthem last decade, I seriously thought about trying Usher D2 (huge horns) and SoundLab A1. No room now 😢

There are a lot I would like to give a listen to but the ones I most want to try is the Genelec W371A with my 8351B’S. What would be amazing is getting a listen in Morten Lindberg’s immersive studio.
Sometime i would like to hear an avantgarde trio with three basshorns on each side the full monty shall we say. The reason is because i think that they would have a distinct advantage of giving me the live dynamic sound that i like and have become accustomed to.
The MBL Reference, the Focal Grande Utopia, and Magico M6

Not that I could afford them mind you but I sure would like to hear them.
For me my three choices aren’t super high end nor reach for the sky fantasies. I would love to audition and then chose to purchase the "winner" between:                                                                                                                                                                                                                                                           Magnepan 1.7i
Tekton Double Impact
Tekton Moab
Thanks for reminding me. Your discussion of Tannoy and Fyne reminded me of point source speakers.

Because I was interested in a full range linear performance I dismissed point source speakers from my search in favor of multiple driver speakers thinking they can do a better job maintaining linearity at the frequency extremes. After many speaker demos, I’ve settled on the Magico A5 which I should be able to fund hopefully in a few months.

Simultaneously I was looking for another speaker capable of being driven by a flea watt 300B amp. I was looking for uncolored neutrality and frequency linearity while being able to fit into my home (no massive horns). I’ve finally settled on the Volti Audio Rival 100dB, but wishing for the Volti Vittora’s 102dB performance (likely too large for my room). But I should also consider the “point source” speaker
Coherent Audio MGRA 15 Signature 102dB - Fyne and Tannoy seem less efficient

Funny how sonic differences between flea watt speakers seem less important relative what the 300B the brings to the table.  Maybe it’s the difference between accuracy and midrange warmth magic.
Kennyc, I'm very lucky. I have the only speakers I ever want to own. You could say I'm married to them. The Muraudio gets decent reviews but IMHO it is a bad design. The panels are curved which is a terrible thing to do to an ESL as you create a non linear situation. Diaphragm goes back it loosens, forward it tightens. This is the reason they have to cross at 750 Hz. Right in the middle of the vocal range. 120 degrees is to much dispersion. To minimize room interaction you do not want any more than 45 degrees. For the same money you can get Sound Labs 545's. No curved panels and the array covers 45 degrees. No crossover. Much more diaphragm area and linear panels can take much larger excursions without distortion. Add subwoofers ( the Muraudio needs them also) and you will be in heaven. The only thing better will be larger Sound Labs. 
Read Roger Sanders's white papers.  http://sanderssoundsystems.com/technical-white-papers
He is the original designer of Martin Logan's curved ESL panel. 
The legacy Valor for speakers and a hegel h30 with a 818v3 feeding it. Most of the others ive already gotten to hear.
I had the chance to listen at Verity Audio Monsalvat a couple of times. For me I had the chance to hear a glimpse of the Nirvana.
I already have a nice pair of speakers so why would I want to audition another pair? That'd be like watching porn. Why would I want to watch someone else having sex?
Wilson Alexx V. I heard the origianl Alexx in a large room with tons of people and it was defined and dynamic, characteristics that soft bodies tend to destroy. I expect the Alexx V to be an improvement.

Rockport Lyra. I consider in the very best speakers that the sound of the cabinet becomes significant. The Lyra cabinet seems to be the ultimate combination of strength and damping. Plus I prefer closed box bass and Lyra uses an unusual bass tuning that simulates closed box roll off in the 1st octave of bass roll off. The rest of the design is advanced and logical and impressive.
i want to audition in my own modest place, a pair of direct acoustics silent speakers. i like the philosophy of their sound dispersion, which makes for a large but somewhat amorphous stereo sound field where instruments would largely stay put in their place no matter where one sits or stands. i’d love to hear a set of maggie IIIs also, the last time i got to hear those beasties was in 1982 in seattle’s definitive audio. they were playing a direct-disc recording of a bach pipe organ piece. the sound occupied the front half of the room as though i was transplanted to the recording venue. that was an acoustically perfect room with much room treatment, i want to hear them in a more typical bare room with a couch. i also wanna hear a pair of K-horns with a la scala center speaker and special klipsch center channel hafler box. i also wouldn’t mind auditioning a pair of energy 22 pros. i last heard them in another acoustically perfect showroom in northern VA. in 1985 and was mightily impressed, should have bought them but i lived in army barracks then so it was a no-go. and finally, a pair of 1965 IMF monitors, those i heard next to the aforementioned energy 22s the saleman had as a comparison to how well a small modern speaker could compare to a tried and true bona fide large studio monitor. those IMFs had a bass like granite, organ 32’ pedal tones and bass drums vibrated the air in the room as well as the walls and floors/ceiling. very addictive. there was such a sense of sheer ease with those speakers.
Maggie 3.7i and 20.7
Quad ESL 2905 (is there a newer one?)
Rockport Lyra
Thiel CS3.7
Harbeth 40.2

Among mass-market offerings I’d like to hear the Polk Legend 800 to see if they really do what they claim.
Forgot to add, Tannoy Kensingtons and DeVore O/96! Selah and Salk, and even the top McIntosh too. 
New KLH-5
A treasured memory of heyday KLH driven by large McTubes...and never quite sold on ports and plugs.
Alsyvox Botticelli’s

heard them briefly in a massive room at 2019 RMAF. They filled that room completely. Magneplanar design but with grunt guts and extended bass. Like Maggies on steroids. 
There are more prodigious concerns in the works, but here's a little aside just for the fun of it. 

I wanted to hear the 3" soft dome midrange sound in my room again - so I bought one, well, actually a pair. I had reviewed the reasonable Wharfedale Opus 2 M2 Bookshelf Speakers for Dagogo.com a while back. That soft 3" mid was SO beguiling, I almost bought them. I have thought a lot about that midrange performance over the years. Every so often I look to see... 

YES! Pair for sale here, GONE! To me! My condolences to the two "watchers"; I came, I saw, I bought...     :) 

This will not rock my world, but it will be fun! I envision doing up a rig with DAC direct using Schroeder Method of IC Placement to Legacy Audio i.V4 Ultra Amp, and doubling speaker cables to the M2. I consider the 3" soft dome among the most desirable attributes of the PMC and ATC lines. So, Im going after it on the cheap, as a side joyride. I will put them with the Legacy XTREME XD Subs. Good fun. I want to see how far I can take the 3" mid in comparison to others. I never got to fully realize its potential back then, so I'm having another run at it.  :) 

I sure love that soft dome in my ATC SCM100ASLT speakers. I look forward to the results of your fun experiment.
Bayz not yet available base model!
 Heard their flagship Counterpoint model briefly near the end of Axpona 2019. That model left me wondering if it could do all aspects of sound reproduction as lifelike as what I was able to audition with the limited time I had with them at the show. 
All information that I have seen regarding this the past 2 years has been glowingly positive.
Their flagship model is a numbing 6 figure +, however the base model should be much more affordable I would speculate.
Hopefully it will be cut from a very similar cloth as their top 2 models sonically.
Ipretiring, the last thing you want in a room is a perfectly omni directional loudspeaker. What you will get is omni directional room interaction. They are an interesting design. I know several people who would not give them a second look. 
birdfan, An interesting, potentially great design (AlysVox) with one major failing and a potential worry. The major failing is that they are 79 inches tall and will revert to point source radiation at around 200 Hz. They needed to be 8 or nine feet tall depending on ceiling height to maintain Line Source characteristics all the way down. The worry is aluminum foil laminated to kapton or mylar is unfortunately fragile. The advantage over an ESL like a Sound Labs is that ribbons (or planar magnetics) are purely resistive and easy to drive. The ESL however is much more durable. There is no current flow so there is no heat and unlike aluminum it will not deform and crack. Magnepan uses this style of construction for it's tweeters only for a good reason.  
Alsyvox Botticelli’s

heard them briefly in a massive room at 2019 RMAF. They filled that room completely. Magneplanar design but with grunt guts and extended bass. Like Maggies on steroids.

Seems more like an apogee full range on steroids.
I know that those Bayz speakers are supposed to be good, but even if I could afford them, I would never have something in my listening room that looks like it belongs under the sink.
 I can understand how you feel. I at first likened them to the monster in Alien. But to me I find them compelling, and an improvement in appearance over my Tektons. lol
@mijostyn, I can’t agree with you on the theory ’that the last thing you want in a room is a perfectly omni directional loudspeaker." I listened to them and (albeit a short audition) loved them.
I also have heard MBL’s several times and on some occasions thought they sounded excellent.
When available I plan on auditioning the Bayz base model quite extensively.
 Best to let my own ears guide me with careful consideration.
Borresen 05s by far but i would be more than happy if i can afford the 03s one day.