A lot of pretty great speakers mentioned so far. Interesting to see the diversity of small and large panels, small and large dynamics, horns, and omni-directionals. MBL if you have the space to do them justice can be pretty spectacular. I heard a set of custom horns (big ones) in Hong Kong that was one of the finest speakers I've heard. Better than any production horn I've heard - but they are just so big. I think with these threads I would answer big room and small/medium room - HA - then you can give two answers. I would take the big horns in the big room simply because my preference is for SET amplifiers and I've not heard a SS amp or PP tube amp that I think I could live with. Great speakers will merely tell me more about why I don't care for those amps all that much. So a big ole horn Western Electric kind of deal would probably be it for me. Although I find them all to be generally hideous looking.
For the small/medium room I will go with Audio Note. I bought the AN J's ten years ago finding them to pretty much trounce everything in their size class. Then became a reviewer - heard pretty much everything since then and couldn't say that anything really changed my view. Although at least I heard a lot more significant sounding speakers I still came away saying - yes but it's 3-10 times more expensive. Moving to Hong Kong buying the KEF LS-50 but that wasn't going to be a long term solution - so I wound up with the near entry level AN E/Lexus. I tried to alter course re-listening to Quad 2905, Magnepan 1.7, 20.1, Dynaudio Countours, Focal Utopia, Legacy, Revel B&W, more KEFs, Zu Audio, ATC, Sonus Faber, Paradigm, Teresonic, DeVore, Trenner and Freidl, Gallo, Spendor, Magico, Tannoy, Vivid Audio, SandersSound, Harbeth, Reference 3a, McIntosh, PMC, Canton, TAD, YG Acoustics, Avantgarde, Soundlab, Martin Logan, MBL, Wilson Audio, Wilson Benesch, JBL, Coincident Technologies, Ensemble, KingSound, Acoustic Zen, Von Gaylord, and numerous others. It would be a stretch to say I couldn't live with many of these speakers because I think I could. Especially the Higher efficiency varieties but the AN E for me is like the favorite pair of slippers. What I like about them - their unique presentation - is difficult now to live without. The AN E/Spx Alnico Hemp is the model that I lust for but they will come in time as the entry model is always upgradeable at a later date. In a large room I'd move to big single driver and or horns but in a normal room for me the AN E (specifically the E/Spx Alnico Hemp) is still the king of the hill.