The best speaker you ever heard?


In my opinion, the speaker is by far the most important part of the audio system. After all, it is the only part you hear. OK, the other stuff really matters a lot, but without a great speaker... No go.

I am a bit 'speaker-obsessed' I guess, and now I am wondering: What are the best speakers you have ever heard, and what made them the best?
njonker
Apogee .... all of the Apogee full range ribbons are frontrunners, but the Diva, followed by a Duetta Sig, cross the finish line first.
According to Greg's suggestions, which I find excellent, I should have mentioned the Acapella Exaliburs.
I am intimately familiar with the Wisdom 75's, both in their original and second generation. They are not an easy speaker to find an amp for. The woofers are very current hungry and the planars are quite revealing of amp character. Well set up and properly driven, they can create a huge layered stage and be quite dynamic with thunderous lows, at least above 30 hz. Having said this, I have yet to hear a pair that has the delicacy, immediacy and transparency of a well set up pair of Quads being driven by a good tube amp. This does not mean that the Quads are better or worse, only that they have very different strengths and weaknesses and that neither is perfect.
Fcrowder, the Quads driven by a pair of Jadis 80 monos, HP of TAS once called a match made in heaven and by golly, how right he was!
OK...here goes. I will try to make this to the point as possible: The Infinity Servo Statics 1-A's were a shocking eye (ear) opener....I never thought a speaker could be so clear and clean and have such a powerful (gut strong) bass....then came the Infinity/Maggies QRS/1-D's....wide,wide stage and very uncolored. The match between the infinity mids and tweeters and the magnaplaner base panel was awesome! What a spactacular system.....The infinity RS 1-B's (my current speaker) was the little brother of the IRS.....it was 1) more affordable 2) retained the wonderful mid and highs and the base went to the basement and moved tons of air.
I am considering upgrading to the Piaga's P-10's.....heard then briefly and will hear them again soon at an audiophile group I belong to...but boy what I hear (briefly) had tremendous promise!!!!!Transparancy, clean, uncolored, efforless.......it's sings!!!!!
But the best I've ever heard (at a dealer showroom) was the Levinson HQD........at Lyric Hi-Fi about a 1000 years ago (lol)....sounded at one point to be really...real.
Anyway, anyone want to comment on the Servo's? QRS/1-D's? RS-1-B's?, Piega's?, HQD's???????