* the 360 has a better games library right now. anyone disagreeing is just plain wrong. it's slowly BEGINNING to improve on the ps3, but there's over a year of 360 releases to compete with
* the 360 hardware isn't very reliable compared to the competition, but MS are pretty good at sending replacements (although not quickly)
* 360 online is infinitely superior, but costs money - about £40 a year if memory serves
* for the most part, multi-format games on 360 look better & play smoother than on the ps3 (e.g. orange box, PES, pretty much any game you could mention
tbh)
* in the end, the decision has to come down to games. make a list of the games you want to play, for both systems, and buy the console with the longer list
* the ps3 platform is more "open", e.g. games like ut3 might get mods & maps on the ps3, the best you can hope for on the 360 is paid map packs
* the ps3 is a little bit more dumb in many cases, e.g. the battery on a controller will drain if you forget to explicitly switch it off
* the lack of blu-ray drive on the 360 is starting to hit a crunch for space-centric games, e.g. ut3, but works in its favor for smaller games (as dvd is faster)