I hate when people come and bash one over the other, without having actually owned both. I myself have both, The xbox I put some sort of cooling unit on the back, so it has never over heated. The Ps3 is cool, but the xbox kills it with their games. So far the only two I have liked were Gow and MW2. I like that the PS3 has free online gaming, but it is not as appealing once I realized there was only one game I liked to play online. I had x-box live for a while but forgot to pay when mine ended.
Look at the games you want to play, and then choose the system, because in the end its not the name of the system that counts, its what you like to play.