I nominate this company as building best speakers!

There are so many speakers out there it boggles the mind. I find it helpful to group them in categories by technology; Dynamic, horn, planar magnetics, ESL and Line Source. I think everyone should go out of their way to listen to examples of each and decide what kind of sound they like. Compare them with the experience of live music in various venues.
Some people do not care to emulate the live experience. Whatever.
Decide if you prefer the large soundstage of a line source vs the smaller one of a point source. Then compare open dipoles to enclosed speakers and finally horns to regular dynamic drivers. Many people choose speakers based on the amplifier they are using. The SET group does this.
IMHO that is backward. You chose the amplifier to drive the loudspeakers you like.
There are many decent loudspeakers out there. Most of them are enclosed dynamic speakers because they are the most commonly produced driver and can be reasonable sized. Any major "breakthroughs" are more likely to be marketing hype. It has all been done. The only significant new development of recent time is the use of more exotic materials in enclosures such as composite and aluminum. The prevalence of CAD mills makes this much easier to do without human labor. Wilson was the first to do this. I believe it was Dan D'Agostino who started using aluminum in subwoofer enclosures.  

@kw6 , The modern one way SoundLabs are a way different beast from what you have mentioned. They are more efficient, will go very loud, are virtually impossible to break and have a near perfect dispersion pattern minimizing room interaction. Read the reviews. I just wish it was easier for people to hear them. As far as detail, transient response and distortion levels are concerned they are far  beyond any dynamic speaker system. 
richop, I really like Magnepans and have set up many of them up for other people. I owned Tympanys for two years but IMHO anything smaller than the 3.7i is not worth listening to and none of them come remotely close to a full range ESL. The best ESLs are not anything. They are not bright or dull or fatiguing. They are whatever you hook up to them. Driven by appropriate equipment ESLs are magic. Magnepans are great speakers, better than many if not most dynamic speakers. They punch way above their price point but they are not even remotely close to the best full range , line source ESL. I should say that the tweeter in the 20.7 is the best tweeter made. It just plain sparkles. 

@kw6 , yes, by all accounts these are excellent and at $30K not a terrible deal in the world of high end dynamic speakers. They will still need subwoofers and 100 watt class A mono amps. If space is limited I think they are a great choice. However, Sound labs 545's are a better speaker at a lower price and they do not take up that much more space as they are only 24" wide. Soundlabs speakers are also immortal. You have to shoot them to stop them. The Sound Labs will be more detailed, are subject to much less room interaction and will produce a more life sized sound stage. They will still require subwoofers for the best performance.
@faxer , Having owned Apogee Diva's for six years I can tell you that I have never been so vexed by a loudspeaker. But at the bottom of it all is ribbon speakers are easy to damage and very unreliable. Even Magnepan's vaunted ribbon tweeter is subject to blowing. They have an ongoing tweeter replacement program. This issue was one of the reasons Apogee died. If you look online you will notice a that replacement ribbons are sold alongside ribbon tweeters. Replacing a 6 foot tweeter ribbon is quite an experience. Only the factory can replace a woofer ribbon. Because there are great and very reliable ESLs available there is no reason to go for ribbon speakers.