What is the most FUN pair of speakers you've ever had and why?

Not the most expensive, not the best reviewed, not the biggest, but the most FUN.  You know, that ONE that just makes you throw on some more music and keep listening, the one that makes your toes tap, your head bob, your ass move the most.  The one that makes you think to yourself "damn, why doesn't everyone have a pair of these?" Let 'er rip. 

I think they sold for about $2,000 new. I will be buying a pair of rebuilt Quads 57's in the near future.  That's another speaker that has a midrange to die for.
Apogee Duetta Sig driven by Krell KSA150 from 1989 to 1999.

It gave fast and exiting sound although it wend to 35Hz or so.

I replaced it with Avalon Ascent II to get sub bass.

But I should have kept it until it got out of order although Avalon is not that bad either.

2 weeks ago, I got Raal Sr1a headphone with ribbon driver which remind me of Apogee Duetta Sig with fast and open sound.

Now Raal Sr1a will be my end game headphone.
For me it was the Polk Audio LSi 15

Not the most refined, and far from the most expensive I owned ( those would be a couple of Verity Audio speakers I owned in the past}.

The LSi 15 sounded...RAW, alive and very dynamic. No exceptional bass, or high frequencies, although those ring radiator tweeters were pretty good.

Can still be had for audiophile peanut$, I remember reading a review that mentioned they compared to 5k speakers, and they did. I had a big McCormack 225 amp and Cary tube preamp at the time. But the Polks sounded great even with the diminutive Arcam A85 integrated. That last inexpensive combination could still be an extraordinary bargain today.

A lot of fun with no bragging rights, but amazing performers still.
Man, this was long time ago, but here goes. I had just gotten ripped off by the local music store owner for a pair of John Zeer speakers. I lost $380 of really hard to earn dollars back in 1975. That got me starting to look at the other end of the spectrum. If JZ was crap, then what was the best (according to a high school junior)? From what I could gather in my cowtown in Wyoming, it was the K horns. Great, how much? Too much for me. Then I discovered Speaker lab in Seattle. They had a kit in which you could copy the Khorn design called the Speaker lab K. Ok, so I built the pair in my senior year in woodshop. Everybody was shaking their heads. Why was the driver inside the cabinet like that? 
 When finished, I was to never hear bass like that ever again. The midrange and tweeter horns were ok, mind you but the bass was pant leg rattling. What more fun could any high school kid have than to own a pair of these?
They were Speakerlab K's for me too!  Sometime in the early 1990's one of my coworkers took a job in Alaska and did not want to transport his pair all that way and asked if I was willing to give them a home.  I do not have them anymore, but only because the octagonal configuration of my current residence is simply not corner horn friendly.  I very much miss that 'massive' sound though!