There is one other speaker line with high effiency that I should have included on my list above: the Legacy Audio line. Their Focus 20/20 is quite efficient (rated at 96db sensitivity, as I recall), and a very fine speaker. I had my first chance to hear the 20/20 (and their much larger brother, The Whisper) about 2 months, and I was very impressed. Legacy is building some fine speakers (if you don't mind their rather clunky styling).