Okay, everyone; get ready for a rather long list of my game collection:
PC:
The Orange Box
Ultimate Doom
Doom 2
Final Doom
Quake
Quake II
Quake III Arena
Counter-Strike: Source
Iron Storm (not Ion Storm, it's a 2004 FPS based on an alternate reality where WWI lasts until the 1960's)
Wii:
Wii Sports
The Legend of Zelda: Twilight Princess
Super Paper Mario
Mario Strikers Charged
Metal Slug Anthology
Super Mario Galaxy
Metroid Prime 3: Corruption
Dragon Ball Z: Budokai Tenkaichi 3
Super Smash Bros. Brawl
Resident Evil 4 Wii Edition
Virtual Console:
Super Mario Bros. (NES)
Street Fighter II (SNES)
Blazing Lazers (TG-16)
Street Fighter II Turbo (SNES)
Super Mario World (SNES)
The Legend of Zelda: Ocarina of Time (N64)
Ninja Gaiden (NES)
Sim City (SNES)
Gamecube:
Super Smash Bros. Melee
Sonic Adventure 2 Battle
Sonic Mega Collection
Mario Kart: Double Dash!
Mario Golf: Toadstool Tour
Mario Power Tennis
Sonic Heroes
Shadow the Hedgehog
Mortal Kombat: Deception
Soul Calibur II
Megaman X: Command Mission
Resident Evil
NHL 2005
Medal of Honor: European Assault
Dreamcast:
Sonic Adventure
Crazy Taxi
Resident Evil: Code Veronica
Soul Calibur
Capcom vs. SNK
Headhunter (PAL)
Resident Evil 2
Wild Metal
Starlancer
Ooga Booga
Test Drive 6
Resident Evil 3: Nemesis
Street Fighter III: 3rd Strike
Quake III Arena
Nightmare Creatures II
Hydro Thunder
South Park: Chef's Luv Shack
Sonic Shuffle
Evolution 2: Far off Promise
Soul Fighter
ChuChu Rocket
Rippin' Riders
Street Fighter Alpha 3
Saturn:
Virtua Fighter 2
Myst
Virtua Cop
Daytona USA
Daytona USA: Championship Circuit Edition
Sonic 3D Blast
Wrestlemania: The Arcade Game
NHL '97
Sega Rally Championship
Sim City 2000
NiGHTS into Dreams
Street Fighter Zero 2 (JPN)
NiGHTS into Dreams (JPN)
Dead or Alive (JPN)
Nintendo 64:
Mario Kart 64
Goldeneye 007
Conker's Bad Fur Day
Super Smash Bros.
South Park
Perfect Dark
Quake
Star Wars: Rogue Squadron
Toy Story 2
Pokemon Stadium
Ogre Battle 64
Donkey Kong 64
Genesis:
Sonic the Hedgehog 2
Sonic the Hedgehog 3
Sonic & Knuckles
Gunstar Heroes
Comix Zone
Mortal Kombat II
Primal Rage
Dynamite Headdy
Vectorman
Contra: Hard Corps
Revenge of Shinobi
Golden Axe
Nintendo DS:
New Super Mario Bros.
Mario Kart DS
Bomberman
Sonic Rush
Children of Mana
Tetris DS
Castlevania: Portrait of Ruin
Ultimate Mortal Kombat
Worms Open Warfare 2
Gameboy (GB/GBC/GBA):
Pokemon Blue
Pokemon Silver
Super Mario Bros. Deluxe
The Legend of Zelda: Oracle of Ages
Warioland 4
Super Mario Advance 4 (SMB3)
Pokemon Ruby
...118 games in total (estimate was close

), console with the most games is my Dreamcast with 23 games, as well as some backups, but those don't really count. Rarest/most obscure games are probably Ogre Battle 64 and Headhunter in this list.