It will always depend, but for me and my tolerance level N64 isn't even tolerable on a powerful PC. For the Pi (3) I don't think it's good for anything except NES, SNES, Game Boy, Game Gear, Master System, Genesis, and TG16 (and maybe some others). Pretty much everything else is poorly emulated or needs more power (Dolphin is decent, but needs power and a Pi even 3 won't cut it even close). Input lag can almost kill any type of emulation. If people notice it in Mario World, try playing NES games that require exact jump timing or enemy dodging or a fast scrolling shooter or one of the best examples is Punch-Out!!. Oi. Lots of YouTube videos on this one.
Most MAME and NeoGeo games work flawlessly on Pi3, same goes for PS1 games.