It sounds dumb but my pick would be the SNES. There’s just something about 16 bit games I love.
The SNES has so many good games, like sf2. The first party games and some good arcade ports.
It also has a lot of good RPGs, like chrono trigger
The controller is really cute
Tho, the PSP is a close second. Tekken dr running at 3x resolution looks beautiful
Yes I’m a sucker for dpad centric devices. Yes i love emulation.
16 bit stuff looks amazing
SNES does have a lot of the better games in lots of great series. Mario, Zelda, Metroid, Castlevania, Final Fantasy etc etc etc.
Though the cheat answer is probably PC since its been around for decades can just evolve with whatever is going on.
It’s obviously pc for me because that’s pretty much all i use for 30 years. But i always liked the nes because it’s pretty satisfying to put in a cartridge and pushing it down.