There were hundreds of platformers back in the 80's through 90's, it was so popular they had movie or show license and created into a platformer, kinda like right now with so many FPS games are flooding out of control just because Call of Duty makes millions of dollars. And yes this is multiple choice, i mean I have more than 4 favorite platformers.
My favorite 2D platformer currently right now is Rayman Origins, I love Super Mario World and Super Mario Bros 3 to death but after playing Rayman Origins I just couldn't put it down, maybe because I grew tired of the 'New Super Mario Bros' so much last year that I lost interest but I know I'll be back playing Mario when the new 3D one comes out. Its not the greatest platformers like all the other sell outs say but its great to see Rayman back in action instead of having stupid rabbits taking over last generation.
My favorite 3D platformer will always be Super Mario 64, the game itself is just so much fun till this day, so much content in a 64bit cartridge it is amazing Miyamoto created this. Especially how every level in the game is a different theme by the paintings. They should really bring that back.