Oh my word! You all have all majorily dropped the ball here and forgot a great platformer....
APE ESCAPE!!! The PS2 and PSP versions were junk until they finally game out with Ape Escapre 3 for the PS2
Ape Escape for the PS1 was just fabulous. Put that one in your editorial Rocket Pig.
Mario is great of course.
Others I enjoyed: Adventure Island, Spyro, Crash,