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
Likely the PS2. Simply for the breadth of stuff it can play.