Yeah, the Gameboy Advance SP is the best handheld ever released. I think it might be the best for years to come. There are so many damn games on it, and many of them get incredible reviews. I've never been into handheld gaming (I've owned many Gameboys), but the SP made me a believer. I put almost 60 hours on Final Fantasy Tactics Advance. Advance Wars and Advance Wars 2 are incredible, and Metroid Fusion can't be missed. There are simply a huge amount of must-play games on it.
The SP is one of the best purchases I've made. I actually think I've played it more than my XBox now.
-Lasereth