Neo Geo Pocket it was out 3 YEARS before GBA and had better graphics. it also had an amazing lineup that included:
Faseli!: A mech strategy game that was extremely customizable
Capcom VS SNK: was an amazing fighting game that had all signature characters and an OLYMPICS MODE
Metal Slug: Im a Fanboy
Bust a Move Pocket: See Metal Slug
Sonic Pocket Adventure: Sonic the Hedgehog with Graphics Identical to the Genisis Version
Bio Motor Unitron: An RPG that allows for customizable robots and the fuzion of new parts, and had dungeons you could explore, tourneys you could enter and etc.
It was Graphically Unparalleled at the time for a portable console, had a strong lineup and had a series of games that appealed to a large fanbase. The console also had a built in horoscope, alarm and clock function that nintendo did not have until the Nintendo DS was released.
Here is the wikipedia article for those of you who question any statement I have made.