Some folks think that the Quad 57 and/or 63s are still the best speaker ever made. However, they do typically take a greater amount of care and feeding than do a typical dynamic speaker.
Again, some folks think a Klipsch K-horn with modern updates is the best of the best.
Recent variations of some other older designs are also very good. A couple of examples are the current version of the Magnapans and Vandersteens.
Enjoy,
TIC