How about on "each" platform?
Commodore Amiga - "James Pond 2: Robocod"
Commodore 64 - "Ghostbusters"
PC - "Carmageddon" (with "Stunts: 4D Sports Racing" a close second)
Mac - "Photoshop"
Atari 2600 - "Yar's Revenge"
Atari Jaguar - "Tempest 2000"
Sega Genesis - "Toejam & Earl"
Sega Saturn - "Baku Baku Animal"
Sega Dreamcast - "Chu Chu Rocket"
Playstation 1 - "Wipeout XL" or "Micro Maniacs" (tie)
Playstation 2 - "Katamari Damacy"
Playstation 3, XBox, XBox 360 - buy me one and I'll tell you.
Nintendo Entertainment System - "Duck Hunt"
Nintendo Wii - "Epic Mickey" (soon.)
Atari Lynx - "Chips Challenge"
Nintendo Gameboy/GBC - "Tetris"
Nintendo GBA - "Tron 2.0" (for the minigames)
Nintendo DS - "Space Invaders Extreme"
Sony PSP - "Echochrome"
but overall? I'd say #1:Tempest 2000, #2:Katamari Damacy, #3:Carmageddon