???What's The LEAST Expensive "End Game"Amplifier You've Ever Heard???

Chances are those with “end game” amps also have speakers that the amp can drive well. So both together is what really matters.

Also worth noting features matter a lot with integrated amps. Different users will have different needs. So sound quality alone is not everything when it comes to integrated amps.

I’ve had a Cambridge Evo 150 for a couple years now and finding it hard to justify any change.  I’ve had a Bel Canto C5i for a number of years now.  Technology has evolved so so am sure I could do better but that little gadget still puts a smile on my face every time. 

Classe CAM400 mono blocks. I have them for over a decade now and enjoy tremendously. Or you can get the stereo version. Either version is affordable now. No moving parts. Dead quiet. 

Anything by David Berning.

My Primare I32 is it for me. They are up to model I35 now with a bunch of add-ons like built in DAC, and network player modules that boost the price to $4,500 minimum. If you don't need 150 watts the I25 lists for $3,299 new and delivers 100 watts. These are in the Class D category but use proprietary power modules that operate on a unique principle. I find the sound to be crystal clear, but very natural. 

There are 3 Primare integrateds for sale on this site right now ranging from $3,00 to $800. https://www.audiogon.com/brands/primare-systems

The Primare I32 was compared favorably to the Belles Aria in several reviews back in the day (the 132 come out slightly on top) so that would be a good bet, also.

Aavik U-150 used at 8K if you are lucky enough to find one.