A few of them are fanbox art.
3DO - 5
Amiga - 407
Arcade - 160
Atari 2600 - 24
Atari ST - 23
Atari 800 - 97
Commodore 64 - 127
Coleco Vision - 36
Nintendo DS - 76
Game Gear - 20
GameCube - 52
GameBoy - 26
GameBoy Advance - 53
GameBoy Color - 42
Genesis - 108
Intellivision - 21
Jaguar - 5
MS-DOS - 273
Nintendo 64 - 40
NES - 60
PC-Engine - 2
Pinball - 4
Play Station 1 - 127
Play Station 2 - 85
Play Station 3 - 4
PSP - 112
Sega CD - 16
Sega Dreamcast - 59
Sega Master System - 26
Sega Saturn - 23
Sharp X68000 - 12
SNES - 74
Vectrex - 14
Wii - 4
XBox360 - 1