SNES: (I never owned a snes when I was young, my neighbor had one I played. I find it awesome that I was 8 and playing SNES on my PC, that's how I grew to love it)
Megaman X 1-3
Super Mario World
A Link to the Past (I had the rom, played and beat the game, but I played it more on the GBA remake)
N64:
Super Smash Brothers
Ocarina of Time
Majora's Mask
Pokemon Stadium 2
Gamecube:
Super Smash Bros Melee (Favorite game. Close tie with Pokemon Gold/Link's awakening)
Wind Waker
Twilight Princess
SpiderMan 2
Soul Caliber 2
Sonic Adventure 2 battle
Pokemon Colosseum
Pokemon XD: Gale of Darkness
Luigi's Mansion
Wave Race
Gameboy Color:
Pokemon Red/Blue/Yellow and Gold/Silver/Crystal (Played and beat them all multiple times on each Gold and Red are my favs)
LoZ: Links Awakening (Favorite Zelda, close tie with WW/OoT)
LoZ: Oracle of Seasons/Ages (Two amazing games that everyone should play)
Wario Land 2 and 3
Gameboy Advance:
Megaman Battle Network 1-6 (Awesome series, favorite is 2)
Wario Land 4
Super Mario Advance 2
LoZ: 4 Swords + ALttP
LoZ: Minish Cap
Megaman Zero 1-4
Megaman and Bass
Sonic Advance 1-4
Fire Emblem
Mario and Luigi SuperStar Saga
Pokemon Sapphire/Emerald
Pokemon FireRed
Nintendo DS:
Phoenix Wright Ace Attorney/Justice for All/Trial and Tribulations/Apollo Justice/Miles Edgeworth
The World Ends With You
Pokemon Diamond/Platinum
(the upcoming Heart Gold will be here)
LoZ: Phantom Hourglass/ Spirit Tracks(ST was the better game hands down)
Jump SuperStars/Ultimate Stars
Nintendogs
Megaman Battle network 5 double team DS
New Super Mario bros
Mario and Luigi Partners in Time/Bowser's Inside Story
There is no way that I can pick a favorite system, these are what I grew up on, they are all my favorites.
SS