Super Mario Bros. 2 and Super Mario Sunshine are the only two crap mainline Mario games.
And I disagree with this, assuming you're talking about the worldwide Mario 2, and not the Japanese one. Japanese Mario 2's not very good compared to the original.
I thought Mario 2 was one of those game with a lot of new ideas that worked out really well. It's also notable for introducing a ton of now mainstream Mario enemies, and it has a great soundtrack. That's an argument for another thread, though.