The best speaker you ever heard?

A well set up MBL 101 (E and onward) radialstrahler is the most impressive speaker I've ever heard. At certain shows, wandering into the MBL room makes every other speaker sound like drivers and boxes. Their top end was unique IMO. I've never heard cymbals truly sound just like drum cymbals in a room, vs "hey, those tweeters are pretty good" type sound. (And I don't just find them spectacular in terms of the obvious soundstaging: I found their reproduction of a kaleidoscope of believable timbral colors to be incredible).

I also heard them at some more controlled set ups. Finally got hold of the small stand mounted 121 version, which aren't of course as spectacular, but they still have to my ear almost uniquely natural upper frequencies.

I've never heard Magicos though, and would really like to.

All speakers being compromised it's hard for me to single out "best."

But in terms of realism, the most realistic sounds I've ever heard from a speaker came from the MBL 101s (one time at a reviewer's house, another at a dealer).  It made all other speakers I've heard sound like they were just "trying" and like collections of boxes and tweeters.

That's not to say the MBLs are perfect of course, just that when playing the right material I haven't heard anything that real.