What are some of the most underrated and overrated loudspeakers you’ve auditioned?

For the money, a pair of 300 dollar Elac UB5 is hard to beat.  Sure, it's not a high end speaker, but for 300 bucks it is a damn good speaker.   The difference in sound between that and other more expensive speakers can be minimal.  

For me the KEF-LS-50. I tried to like it but eventually ended up selling it. Way overrated in my opinion. I tried it with many different amps and configurations  and in different rooms. Nothing seemed to work for me. 

Still using the Dahlquist DQM-9s. To me the quality and sound for the money I have not found better. Sure overtime they need to be re-foamed and maybe new caps but after all these years, still happy. Also like the older Infinity.

in re: millercarbon Most overrated? Easy. Vandersteen.

LOL. The Vandersteen 2CE in all its iterations is one of the best-selling speakers of all time, for a reason. Great value. I’ve owned a pair for 20 years and will be getting the latest version soon, only because I can’t afford the Treo CT or Quatro CT. The Quatro CT, in the >$15k price bracket, has some good competition, for sure. I recently auditioned them powered by a full AR stack ... stunning. Note: I’ve been to more than a few hi-fi shows and heard systems fetching >$100k or well beyond.

I’m a Vandy fan, but not a fanboi. I have been trying to find and consider other floor standing "full range" speakers that perform as well as the 2CEII and are as good a value, in their price range, and so far it’s slim pickings.

Overrated:
Dynaudio, Totem, Audio Note ( especially price for this kind of 2-way monitors in poor cabinet )

Underrated:
many active speakers : Backes&Muller, Geithain
they play so much better than passive in similar price , and You dont need any ( expensive ) amp