Mario hasn't changed a whole lot, whether you're getting to a star or getting to a pole, it's the same thing. Mario World was kind of a step down, and (while many disagree) I felt Mario 64 was a step further down. Mario Sunshine and Galaxy have stepped it up though, and Galaxy is my personal second favourite behind 3.
I don't like comparing stuff to Mario 3, because I feel like saying movie A, movie B, and movie C suck because they don't compare to Citizen Kane, or something like that. Mario 3 was THE game, it was Miyamoto's masterpiece (though many would argue Ocarina of Time, it is one of those two). Just like Will Wright has his Sim City and Sid Meier has his Civilization 2.