Many different things you have to take into account.
The big thing is which system are your friends playing.
And sense I now much more about ps3 Ill just post stuff about ps3 and let someone with xbox post things about xbox.
ps3
-If you watch/ buy movies a lot then you should really think about ps3
-If you have patience

-Can play thousands and thousands of ps2 and ps1 games (as long as you get 80gb)
-If you have a psp then the ps3 will greatly benefit it.
-The online isn't amazing, but its free and it does what its suppose to.
Those are just a couple things, not talking about games and stuff like that. Because both consoles have just about equal amounts of games coming out. Its all about preference.
fyi-Dont expect this thread to stay up for too long