I prefer my elite to my ps3, the controller is much more comfortable, i get cramp in my hands using the ps3 for a while.
Xbox games are usually a few quid cheaper.
More of my X games are in full hd. (although its hard to tell the difference IMO)
i prefer the looks of my elite as it fits in with the matt finish of all my other equipment.
i think game play wise only the die hard gamers can GENUINLY say there is a difference.

As someone previously posted with the price drops bringing both consoles into the similar brackets, go for the one that most of your mates have.