Speakers least affected by room acoustics

Spendor S8e!  And the Spendor SP-1 but to a lesser extent. 

Thank you everyone. All info and opinions much appreciated.

No disrespect. After all you are the Audio Doctors! (and I am merely a physician, haha.) Never the less, I would say that with a dipole the sound perpendicular to the panel is canceled because of opposite polarity. So less side wall pressure and less ceiling pressure. The proportion of direct sound to the listening position relative to the reflected sound is greater than it would be with a conventional speaker. Sound pressure diminishes with distance (3 dB per foot if I remember correctly.) The ceiling reflections are not even 1st reflections, but 2nd or 3rd+ reflections at best, and so are much diminished in volume on that basis. Since the OP doesn't want room treatments clogging up the decor, I prefer to stand by my assertion that panel speakers will help to minimize room acoustic problems. I've had many electrostats and many box speakers. In my experience stat panels cause fewer room acoustics problems. On the other hand, I am like everyone else on these forums. I'm pretty sure of myself even when I am wrong. ;)

The only thing I would add is that the rear wall directly behind the panels could be an issue, which is why panels are usually recommended to be placed way out away from the rear wall since the reflection waves would interfere. Also, toe in of panels could increase the possibility of side wall or rear corner reflections.

I find it baffling how people will drop thousands upon thousands of dollars on equipment (and thousands on cable - which I find rediculus for multiple factual reasons I won't get into here) but limit their budget severely when it comes to accoutic treatment.                                        Sadly, it's no different than a guy who thinks that buying a more expensive set of golf clubs is going to cut off 15 strokes from his game (hire the Flippin golf coach for crying out loud and get a much greater return on the hard - earned dollars or keep dropping thousands for miniscule improvents - then continue to whine in frustration just like the rest of the cluless maggots...)