Super Mario World I got the 96%
Super Mario 64: all 120, which gives the secret Yoshi thing
Super Mario Sunshine: all 120 gives you the Hawaiian shirt and sunglasses I think to wear
Super Mario Galaxy: all 120 gives you the ability to play through as Luigi, get 120 with him, and there's one more challenge.... I never got the 120 with Luigi.
Super Mario Galaxy 2: After getting 120, there are another 120 green stars, and then the last 2 stars.

So out of all those, the Luigi play through on Mario galaxy 1 is the only thing I haven't done. Mostly because you're getting the EXACT same stars again. If I ever go back to play through, I will just pick up my Luigi game.
Galaxy 2 was nice because the Green Stars were just hidden in the levels, so it was completely new challenges.

THE JACKEL