question

in our house we have a few gaming consoles, we have an xbox downstairs, we have a ps2 in the daughters room, we have a nintendo ds floating around and also a nintendo gameboy advance around somewhere as well, the xbox i hope to be replacing with an xbox 360 in a few months but only when i have researched more abou it and found out which xbox original games will work perfectly on the 360, as i don't fancy paying £50 for a game when i get get older games for £5 and less