I won’t say I have a favorite, I too have heard great examples of all types. However, as both a reviewer and tweaker who constantly is moving amplifiers around, I can confidently say I love Class D amps with SMPS supplies. They are just easier to manage.
I used to DIY amps quite a bit, building from either pre hilt modules, kits, or even of my own designs. I’ve built numerous linear power supplies including capacitance multipliers and CLC supplies with inductors the size of 1kva toroidal transformers. I measured their behavior along with a lot of computer modeling.
There is a quality to SMPS that I think deserves both mention and discussion. They need a little love.
An SMPS supply is inherently regulated. This means the voltage doesn’t drop with load. Instead it regulates the voltage until it hits its limit. This is good for maintaining output under varying load conditions and under highly dynamic conditions. It also ensures the amp distortion and noise doesn’t suddenly rise at the limits. Linear supplies without regulation can’t do this and thus need to either be very large with huge capacitance or use a complex CLC method like i did, which is really expensive and really heavy.
The limitation with SMPS is that you can’t treat their maximum current delivery rating or wattage rating the same as linear. If you consider it like an amplifier, linear soft clips where SMPS hard clips. When a linear supply approaches its limit it just gradually drops the voltage as current increases (which is actually fine for low impedance loads) until it hits a limit. The ripple increases as well, so a lot of capacitance is handy to avoid that. An SMPS won’t reduce voltage, it just hits its limit and a current limiter kicks in. It leads less headroom. I built a 300 watt per channel amplifier (Class A/B) and included a 1200 watt SMPS supply designed for audio use. It couldn’t even reach 300 watts rms before the limiter kicked in. Yet a 1.2kva toroidal transformer and 40,000uf of capacitance would have been plenty with a linear supply to exceed that rating. Instead the amp needed twice the power supply to reach its expected output. In other words, an SMPS doesn’t have to make an amplifier less dynamic, manufacturers just need to start including much larger ones. Like twice as big.
Another nice attribute of the SMPS is that their ripple voltage is on par with the very best linear supplies possible with advanced filtering. No basic RC linear supply can even compare. While many might point to switching noise in SMPS, fact is, in modern well designed Audio grade SMPS, there is no meaningful switching noise on the output. They do have high RFI radiation, but that is easily filtered out. In the end, I think we all need SMPS in all amps.