Here's my GBA favorites:
Pokemon Emerald
Dragon Ball Z - Supersonic Warriors
River City Ransom EX
Final Fantasy Tactics Advance
Shining Force: Ressurection Of The Dark Dragon
Shaman King Legacy Of Spirits Soaring Hawk/Sprinting Wolf
Advance Wars 2 - Black Hole Rising
Crash Bandicoot 2 - N-Traced
Power Rangers - Dino Thunder