Hmm... Lets see here... I think I'll have to narrow it down to my three top favorites for both 2D and 3D.
2D:
-Sidescroller/Platformer(Mario, Metroid, Donkey Kong, Megaman X, etc.)
-Fighting(Street Fighter, Killer Instinct, etc.)
-Maze/Puzzle(Pac Man, Tetris, Bomberman, etc.)
3D:
-First Person Shooter(Timesplitters, Halo, Portal, etc.)
-Stealth Action(The Metal Gear franchise, mainly the Metal Gear Solid games.)
-Simulator(The Sims, Sim City, etc.)