For a five year old, you definately want to buy a Nintendo DS. Game Boy Advance is somewhat outdated, and the DS is compatible with GBA games. NIntendo markets their products as appealing to all ages, and the DS is no exception. It would be very easy for a child to use, and it also features game support with many kid-friendly titles. For more info, check out NIntendo’s website.

game boy.more kid-friendly games

game boy advance.. the psp is far to fragile for a child of that age.
also the gba has more kid friendly games.

Neither. I have seen some great commercials for the new LeapFrog Leapster. That is basically as fun as the other two you mentioned, but it promotes learning. He’s only 5, so that’s probably the best for his age. And of course the Leapster and it’s games are a lot cheaper.
Try Ebay:http://toys.search.ebay.com/leapster_Edu…