N64 easy would be an easy choice if I wasn't by myself. It was amazing to play in groups. By myself I might have to say the regular old NES. It had a lot of great games. I would just try to beat Metroid till I succeeded.
the nostalgia in me says toe original Nintendo because that's the only one of the 4 I had. The intellectual part says take the N64 because it has more games that will take longer to beat.