I've had my gameboy advance sp since 2003 and i haven't brought another handheld console since. But lately, the battery life is shortening and the light won't work anymore. Also, I feel it would be a waste of money sending it to nintendo to get it fixed.
On top of that, I would like to get back into playing more newer handheld games. I thought of buying the Nintendo3ds but I don't like how its the same price as when I brought my wii($249) and how it doesn't have backwards compatibility past the ds series.
If you have a gamecube, just snag a Gameboy Player. If you're looking at the 3DS, and there's not much out you want just save your money for a while before making a final decision.