I have been listening to the newest Horning Aristotle Ellipse PM65 speakers. They have a rated 96db efficiency, but in real life are very easy to drive. A few watts will do it beautifully. It is a horn loaded hybrid design that is not very large. This speaker is incredibly fast, dynamic and so pure sounding. They offer most all of the sonic benefits of a large, fully loaded horn design in a more traditional form factor a size.
In general, I also find higher efficiency speakers sound more real and lifelike, at least to my ears. Here is a link: