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

Coda S5.5

The very best sound quality is from single-ended amps. But they typically have too low power output for most speakers. The next best sound is Benchmark AHB2. 

Here's my review:

Benchmark AHB2 Power Amplifier – 10 Audio

BMC CS3 from Germany. 8,000 Euros. The catch is it must be paired with another BMC dac or source.

@imjerrys I know reviewers and friends that have long term experience with the AHB2 say the AHB2 sucks all the soul out of music. 

But others also really like them. I don't quite understand if this is a gear mismatch or what. But the AHB2 falls into my weird list.

The very best sound quality is from single-ended amps.

@imjerrys They don't really make proper bass- most SETs that make 7 Watts or more can't make full power at 20Hz. The output transformer simply lacks the inductance to allow it. If it did have the inductance it would be much larger and then wouldn't be able to make the highs.

Distortion is quite high, which is part of the lush quality, but that distortion also obscures detail. 

You can have amps that are much lower distortion so are more detailed, but every bit as smooth, while also making proper bass. So SETs can be fun, but in no way are they the 'best'.