Here is my list:
GB & GBC
Links Awakening
Link Awakening DX
Oracle Of Ages
Oracle of Seasons
Fifa 98
Alien 3
Quarth
Alleyway
Test Drive 5
Bugs Bunny & Lola Bunny
Turtles: Fall of The Foot Clan
Mega Man 2
Mega Man 3
Super Mario Land 2
Super Mario Land 3: Wario Land 1
Wario Land 2
Castlevania Adventures
Wizards and Warriors X (you know, that platformer from Rareware)
GBA:
Minish Cap
Golden Sun
Final Fantasy Tactics Advance
Spyro-Season of Ice
Game and Watch Gallery Advance
Metroid Fusion
Metroid Zero Mission
Advance Wars
Wario Land 4
Yoshis Island
I think that's all. I keep them in a box that's getting too small. Need to find a bigger box.
Recommendation:
The box says that there are only 6 games, but in fact there are 20. No, really. You can unlock 14 games by getting more points in the single games and 11 of them even allow you to choose a more modern graphical style. If someone wants to know about G&W games, they should give it definitely a try.
I personally also really like Wizards and Warriors X, but others seemingly don't.