Right now none, but I do have suggestions. If you like platformers, Sonic Advance series are an absolute must-have for every GBA owner. If you're into RPG's, get both Golden Sun's and Summon Nights 1 and 2, 3 is only in Japanese as far as I know. If you prefere more western RPG's, I thoroughly enjoyed Baldur's Gate - Deadly Alliance. Mario Kart: Super Circuit is another game you don't want to miss if you like the series. Doom Advance is pretty good too, but you can play the superior ports or the original so it's optional. If you enjoy strategy games, give Advance Wars 1 and 2 a try - they're essential titles. Castlevania games are also solid. Check the GBA Essentials list for more titles.