I would have to say Im a PS3 person, this is mainly because I already owned a load of PS2 games, and my PS2 has just broken, So buying an X360 would have meant throwing them all away.
Most of my friends IRL have a PS3 anyway,although if I had the money I would get an X360.
I also use my PS3 for steaming films via the media server, meaning I don't have to transfer all my films.