The games listed above are really good suggestions, and I can recommend a few more:Game boy:
Wario land 1
Mario land 1 and 2
Mega Man Dr Wily's revenge
Final Fantasy legend
Kirby's Dream Land 1 and 2
Pokemon Yellow
Game Boy Color:
Wario Land 2 and 3
Oracle of Ages
Link's Awakening DX
Mario land 1 and 2 DX
Dr wily's revenge dx
Wario Land 1 DX
Castlevania the Adventure DX
Dragon Warrior 1+2
Dragon Warrior 3
Pokemon Crystal Fancy dresses
- Donald Duck - Goin' Qu@ckers
- Elevator Action (European release based on the arcade game, but adds a lot of fun little features)
- Tomb Raider: Curse of the Sword
- Lufia - The Legend Returns
- Montezuma's Return (if you can stomach the annoying music)
- Shantae