do you think you want to play blueray discs, because ps3 can play blueray. thats why i bought mine. i mainly use it for watching movies and recording/playing back/pausing live tv (you need playtv to have that feature). If its just for games, just pick which one has more games you like. They are pretty similar performance and gfx wise.
Get a Wii
JK, unless you really want it. They are practically the same. The only difference in PS3 has Blu-Ray (which does not improve graphic quality to a noticeable extent) and Xbox Live has a fee (but offers more than just multiplayer). If you want a console primarily for gaming, especially FPS, an Xbox 360 is a nice choice. If you are looking for a media center as well as some going here and there, a PS3 would meet your needs.