To be honest this is not the year for hard core gamers to buy a new xbox and I will not suggest it as well. Since by late this year or early next year new generation consoles will be launched. And by Feb. 20 Sony Playstation will be making an official announcement.
My ten cent on this one though.
Fun Factor - You can go either way PS3 using the PS3 wand or XBOX using the Kinect for sport games and fun as well. So that a kid can get exercise while indoors.
Quality Wise - Though I work for xbox I would say quality goes to Sony Playstation: This is by experience professionally and as a gamer.
Games - both console has wired variety of fun and learning games you can chose from for kids. You can buy a console that is of any region and just have it modded to play downloaded games via the Hard drive since your kid will most likely not go online on it.
Basta importante malingaw imuhang bata and di mo mag mahay sa inyo choice.