Anything'll do. Kids that age don't get frustrated as easily when they're losing, especially if you keep encouraging them.
However, to keep their interest in the game, get them games with their favourite characters in.
May I suggest a PS1, or N64, they're too young to give a damn about AA or bloom, and they have many great, cheap titles. You could get Crash Bandicoot, Rayman, Spyro, Gex, Tony Hawks, Croc, Tekken, Micro Machines, A Bugs Life, etc on the PS1. And Mario 64, Mario Kart 64, Donkey Kong 64, Banjo Kazooie, Wave Race, Pokemon Snap, etc for the N64.







