#1: NES #2: SNES #3: Wii #4: Nintendo 64 #5: GameCube
Handhelds? Those are harder to rank. I feel like all of Nintendo's portable systems were amazing, except for the 3DS, which I'm disappointed with. Of course I'm completely ignoring the Virtual Boy, which I feel doesn't really need to be discussed.
[Edit: Forgot about the Wii U. Too early to rank the system. I'll have better thoughts on it after this next holiday season and more games.]
http://www.youtube.com/watchmeplaynintendo (Actual game captures - no emulators)
*I never owned a SNES and only had a few friends who had one so I had very limited hands on time with the system and when I did have the rare opportunity to play the system I would end up being limited to playing either Super Street Fighter II or DKC.