8 consoles (Atari 2600, NES, SNES, Genesis, PS1, PS2, N64, Gamecube) and the Game Boy.
Atari 2600: 24 (favorites: Pitfall!)
NES: 20-ish... hell, I can't remember (favorites: Pin-Bot, Bomberman, R.C. Pro-Am II, Super Mario Bros. 3)
SNES: about 20 (Super Mario World, Super Mario All-Stars, Super Mario Kart, Earthbound, Tecmo Secret of the Stars, Tetris Attack, Super Bomberman 2, Zelda, all the MK games, and some craptacular sports games that NOBODY WANTS!)
Genesis: also about 20 (includes the MK games, a complete Contra Hard Corps, the Sonic games, and a copy of Castlevania Bloodlines that may or may not have the manual)
PS1: 24 (highlights: Final Fantasy 7 and 8, both non-GH, FFChronicles, Parasite Eve, PE2, and a disc only non-GH Castlevania that I bought for 3 bucks. Oh yeah, and the almost complete Lunars. SSSC is missing the map that I've been either too lazy or too broke to buy, and because the fates hate me, my Lunar 2 is also one of the many that are missing that fucking pendant.)
PS2: 11. SMT Nocturne, Final Fantasy X-2 that needs a case, GH Kingdom Hearts (it's a great game, does it really matter?), the complete .hack series, DBZ Budokai 1 and 2, MK Deadly Alliance, and Katamari Damacy.
Gamecube: 21 actual games, an overpriced storage program (Pokemon Box), and the Pokemon Colosseum preorder disc.
And finally, the Game Boy. 20 games, including Castlevania Aria of Sorrow, which is well worth the slight loss in value by cracking open the box. Oh yeah, and a wireless adapter.