I used to date a chick who's son had a PS3 (fat) and I watched a couple DVDs on it. I was appalled at how bad it looked. This after watching the same DVDs at home on my Oppo 83. I have no interest in gaming or web browsing, just BDs and DVDs (and DivX, DVD-A and SACD). For that reason, the Oppo is a better choice. If it's gaming and web browsing you want, then of course the PS3 is the best choice.
cheers,
supervij
EDIT: Okay, the PS3 upscaling wasn't all that bad, but the Oppo is simply in a different class when it comes to DVD upscaling.