high-efficiency loudspeakers

Omega rs8 supercone , Tekton Impact Monitor , Yes iam very happy both very dynamic speakers.

I don't know what is the best. IME... I've been using Lowthers for many years though & really like them. They are very 3d (with the right amp), transparent, & throw a huge deep stage. Mike are in fidelio cabinets. If you go that route you'll want to incorporate a sub into your system though. 

The best is a question only you can answer after hearing several different speakers.   I have owned a number of stand mount speakers that were fine, accurate , sounded just like the recording ....  but that's the problem... they sounded like a recording

And then I did something unconventional and out of character for me....   I bought a pair of Klipsch Heresy III

These speakers are awesome.... the scale and weight of live music is possible in my living room.... I have never had more fun listening to music than with these speakers.   I am driving them with a pair of 40 watt EL 34 mono amps and am blown away at how great they sound.