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

My current power amps are the best I have ever heard by far. T+A M40 HV's which are monobloc's  with each having dual High Voltage (hence the designation HV) solid state output sections. It is configurable in "High Current" mode as class A only (about 60 WPC), or in it's "High Power" mode as class A/AB (1000+WPC). So power is adequate for anything, but it is the sound it produces that wins you over in spades!

Hi Guys 
Pass Aleph 0’s
Jeff Rowland Model 2

I’m Surprised that no one mentioned Jeff Rowland especially the Model 12’s which was a major breakthrough 20+ years ago. It changed the game. 

From my experience, though based on difference systems:
Bryston 4B3 and 28B3 monoblocks
D’Agostino Momentum Stereo amp
First Watt SIT-3
Classé Delta monoblocks I heard at Axpona

Funny you should ask-  
I’m right in the middle of a classic solid state cult amp shootout.  I am comparing a Bedini 100/100, Bedini 25/25, Bel 1001, Sunfire 300 and a Forte Model 4a with Soderberg mods including blackgate caps.  I usually run Coincident mkii dragons or a coincident SET, but these solid state amps are incredibly musical and I think I would be happy with almost all of these (the Sunfire being the exception) on a long-term basis.