They are both good systems, that each have good games and features. I won't tell ya what to buy, i'll just tell you what i bought and why.
I bought a PS3(obvious by sig) cause i didn't want to take a chance that if i bought a 360 i'd have tachnical issues.
Some of my friens have 360's so i thought i'd get the best of both worlds.
I liked the PS3 exclusives so that was another plus, especially MGS4.
I knew i'd use wifi, so i'd have to pay extra for that on the 360(at the time both systems cost way more than they do now).
PSN being free was big for me also.
I have a hdtv in my room so i thought i'd get the most out of it, with blu-ray etc. The opening sequence of The Dark Knight on blu-ray is jaw dropping.
Also when i heard about all disks having scratch-proof layering, that kind of sealed the deal.
Edit:Also if you have a psp, stuff like remote play is awesome
