The best speaker you ever heard?

I agree with Adsal.
In the mid 1980's I had a chance to hear the original WAMM's at a demo given by David Wilson.
While I have not heard any subsequent versions of them, I have yet to hear anything better.
Unfortunately, these are not exactly commercially available speakers.
The performance gap between them and something like an Avalon, Dunleavy, Sound Lab (all of which I have heard) is huge.
When Wilson put on a record of a string quartet, I thought I was listening to a "rigged demo" in that there were a bunch of musicians hiding behing those towers actually playing. No other hifi system has ever come close to fooling me like that.

The original $40K B&W Nautilus w/ 8 ML33H Monos. I haven't heard any speakers more expensive than these, however, to date I put this setup above the Wilson Max's, and Avalon Eidions, both of which I thoroughly enjoy. Simply amazing! (Of course we're talking $100K+ worth of amplification. I'm sure one could do as well with better speakers and fewer amps for the same amount of money.) Never-the-less a sight and sound to remember.

Martin Logan Statements (powered by Cello) long time ago. Recently, A-Physics Medea (driven by S-Line Kraft monos). Aural memory failing me, I can't chose b/tween the 2, sorry.
Quite a few speakers suggested above I'd like to hear though...

Since this thread refuses to die, I guess I'll finally chime in.
The finest loudspeaker that I've yet had the opportunity to spend time with had its north american debut in my own exhibit in Las Vegas this past January, courtesy of Toffco, the US distributor for Neat Acoustics.The Neat Ultimatum(US$16K) was an extraordinary experience, with the coherency, articulation and imaging of a mini monitor and a chameleonlike quality that was equally at home with solo vocalists and small combos as it was with large scale orchestral and jackhammer rock.They displayed a sweet openess and spaciousness unlike any other conventionally enclosed speaker in my experience.They are superbly fast, nimble and dynamic.The Neats could float a serene, stable and convincing ly holographic image in the midst of a cacaphony of pyrotechnical fireworks and headbanging volumes.
I found it intriguing to hear comments after the show which ranged from "lush","laid-back" and "silky" to "relentlessly driven" and "kick-ass" all dependant on the character of the recordings used during the audition.I've never heard such a "complete", expressive and alluring do-everything big system.
Ken

I own ESL-63 and I love them but the new 989 are much more neutral and has killer bass compared to the 63.
The Avalon Eidolon is the only dynamic speaker I heared that has the magic and at the same time gives you the strenght of dynamic speakers (I have not yet heared Amati, Lumen-white and Kharma, but I plane to!!)

Ulrik