Here's my GB cart collection. The only things not pictured are Pokemon Green and Link's Awakening which are in my backpack and my Bleep Bloop LSDJ cart with USB.
Just in case...
GB:
Tetris
Final Fantasy Legend
Bomber Man (side scroller - it's actually pretty good)
Tamagotchi
Kirby's Dream Land
Kirby's Dream Land 2
Pokemon Yellow
Pokemon Red
Harvest Moon
Ren & Stimpy Space Adventure
Mole Mania
Metroid II
GB Import:
Peetan (I think this started on MSX or PC88. You drop eggs to turn see-saws so your chickens can climb up to the top of the coop and escape)
Tamagotchi
Tamagotchi 2 (got both of these just for the sticker art)
GoGo Ackman
Super Mario Land
Super Mario Land 2
Peetan (best Game Boy game)
Dragon Quest Monsters (also bought for the sticker art)
Kunio Kun / Double Dragon II
GB Color:
Metal Gear Solid: Ghost Babel
Super Mario Bros. Deluxe
LoZ: Oracle of Ages
Pokemon Puzzle League
GoGo Ackman and Kunio Kun are for sale / trade if anyone wants 'em.
I'll try to post my hardware next.