RetroArch: Emulates nearly every gaming console

[Furby]

Eh, I've tried it in the past.

Honestly, while it's a nice idea (If uniformity in your emulators is incredibly important to you, then this is the emulator suite for you!), but for the most part, Individual apps (My Boy! for GBA, etc) do a better job on an individual system level better.

I'm also not a fan of it's in-your-face game pad, but I'm aware that's subjective.