What is the best solid state amplifier you have ever heard?

To me it’s my Krell FPB 600. Plenty of power when called for  , Big deep bass , Excellent detailed. Excellent in all areas for me. Everything I could want in a ss amp.This  amp is hard to beat. 

First Watt SIT-3

Accuphase pre and power driving b&w matrix floorstanders and being fed by Linn lp12 lingo with some 5 tone arm and ortofon hohmann cartridge. All connected with siltech cabling. This was back in the 1980s .

I haven't heard that many and I tend to prefer tubes myself. With that caveat and the obvious fact I heard each of these with a significant amount of time in between and on completely different speakers/setups:

4) Sugden amps sounded really nice
3) Pass Labs XA30.5 (haven't heard the .8)
2) Pass Labs XA25
1) Nagra Classic Series sounded sublime

amp/speaker synergy makes too much of a difference to pick just one.