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

Klipsch Cornwalls are the best in the line for efficiency and accuracy in my opinion.  I play almost only vinyl and have a very high end turntable and nice amp.  I owned a pair of Klipschorns(top of the line) as well and as far as accuracy and depth of stage I believe the Cornwalls are superior.  I don't know about the new ones but my pair are from the early '80s.

How about Avalon, rockport , and yg acoustics ????

My take away so far is:
"I am happy i don't own B&W speakers." Early on when choosing a desktop system I did a comparison (A-B switch) between B&W & Martin Logan (15's) bookshelf speakers. The B&W sounded pretty damn good and I kept fighting with myself thinking, you can't chose the M-L over B&W. Eventually i just went with what sounded better to me, and in this case it was M-L. So, in the end it was just marketing that i was really fighting with. 
  For the Record, i am currently using Thiel TM3's for desktop application driven my M700's. (no need for subwoofer). This is justified bc i only paid $700.00 for the Thiel's at auction, brand new in the box with stands. And to me, the TM's are pretty damn good sounding speakers although i would not have paid $3,000 for them.  
On the shelf taking a break waiting to be called in off the bench are my coveted & very close runner ups, Burchart S400's-(very fine speaker).
In the big room, "Surround Sound System."
Paradigm Prestige 95-F Towers/Center/Rear Surrounds & SVS subwoofer.  

Someone mentioned Totem.   Yes!  When I hear them and then see all the praise, "over-rated" certainly describes my mindset.
(Again...pure subjectivity...0

Years ago I owned the original B&W Nautilus 800, the pre diamond tweeter version.  Like them in the shop but could never get them to image well.  May have been the 9x13x8 room or the c-j tube amps.  Eventually replaced them with Wilson Watt-Puppy 7s.  Marvelous.  

The point of this is a couple of visits recently to my local top line dealer... a Magico shop, and all powerful high prices electronics.  Nice speakers but for the $$$, not for me.

Admittedly I'm a Wilson guy, now with the terrific Yvette's.  
My local high end guy had just picked up the B&W line to fill in the lower price gap in the shop.  He had set up the new 800 D3, so took a listen.  No more kevlar mid range...good.  But you could hear each driver on each side playing.  Tweeter was tweeting, the woofer was woofing, and the mid range was screaming.  Terrible.  

A couple of weeks later I was back in and there they were again.  He asked me to listen again.  Just amazing.  They needed a few hundred hours to break in and now sounded terrific.  Really gave his $100K Magico's a run for the money.  We both agreed the B&W's, well run in, were a terrific value.  You just never know what your listening town making these comparisons...