a six year old? Wow. That's a little young for the ps3 or xbox. Not sure if there are many kid friendly games on those systems. I have the ps3 and like it a lot. For a kid i would recommend te WII though. I hear there are a lot of kid friendly games on there plus he will get a workout.

PeachTree 65se, PeachTree D5 and SVS SB1000 - Stereo
M80s, M22s, SVS PB3000