This is a fun exercise. Lots of great speakers posted here. However, it might have been more appropriate to impose some constraints on this discussion by specifying a specific amplifier or amplifiers, or costs for the amplification, or cost of the speaker.
Specifically, with respect to the recurring (and probably well-deserved) nominations of the Apogees - they really impose some very significant performance capabilities on the amplifiers (which are rather costly). I mention this because it isn't necessarily unfair to nominate them, but rather that it suggests that this discussion is about much more than speakers and that we are talking about cost-no-object amplifier/speaker systems. That's not necessarily a bad thing, but it might be a different discussion.
It also might have been useful to impose certain requirements on the nominations, such as, 1) best speaker ever heard or 2) best speaker ever owned, or 3) best speaker ever known over an extended period of time. Listening room constraints might also have been useful.