The Wii is definitely one of my favorite all-in-one consoles. I use it for NES, SNES, N64, GB, GBC, GBA, GameCube, & Wii.
It's capable of other retro consoles as well. My PS3 is also currently my all-in-one Playstation console with the HAN exploit with PSX, PS2, PSP, & PS3.
As for the PS4, I'm...