games systems for xmas

[s13eater]

things are tight this year, so i thought of buying the kids a games system between them until i get some bills paid, so any ideas, kids are 11, 10 and 8,i was thinking of second hand, either xbox, xbox 360 or wii, what would be best for their age and are there any faults to look out for when buying them,i was told that the 360 breaks down ! cheers.