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

As already mentioned, an insurmountable degree of variables to answer properly. For entertainment value and in no particular order: Mark Levinson 29, Audio Research 100.2 and Pass Labs Aleph 30. Yes, I have owned all three over time and am currently using the Aleph 30. Have I listened to every amp on the planet, of course not. Are there better amplifiers, of course.

Ayre MX-R Twenty
My other favorite amps are either tubed or hybrid (ARC, Aesthetix)

Plinius SA-102 with a McCormack dna-1 gold revision a close second.

Oz

N.E.W. DCA-33 battery powered, 33 watts per.Real nice sounding solid state amp!I keep one around as backup for my tube amps, sounds great with my Sonist Concerto 4's!

TISH

Spectral Audio amplifier :)
At very first listen it revealed the coloured sound from other top contenders of 200 watts and up. I was amazed at the completely different level of overall refinement and level power output.