gba games

[Momiji]

Golden Sun and Golden Sun: The Lost Age
Final Fantasy IV, V, and VI Advance (when it comes out)
Final Fantasy Tactics Advance
Castlevania: Circle of the Moon
Super Mario Advance 3: Yoshi's Island
Tales of Phantasia

Of course, as you can see by the many suggestions in this thread, the GBA has an amazing and expansive library.

All of those, and the Mega Man Battle Network series.

[Xander]

I loved Legend of Zelda: Minish Cap, Harvest Moon: Friends of Mineral Town, Boktai (play using the sun :O ) , Pokemon Leaf Green, and ummm, I forgot if there was any more I played.

[Hellsnextboss]

Golden Sun and Golden Sun: The Lost Age are great. (I stayed up for 3 days straight with GS:The Lost Age. It was addictive) So is Final Fantasy tactics Advance.