I don't know why people just can't accept that one is indeed better than the other. I play mostly on the 360 so believe me, I'm not a Sony fanboy. The answer is yes, the PS3 has better graphics capability IF you have a developer that can take advantage of that.
The thing is, the PS3 is harder to develop games for. Even so, there are some multiplats that are better on the 360, some that are better on the PS3. Generally, they are about the same. The other thing is, the games that people keep going back to when they say they look better on the PS3 is exclusives. You have nothing to really compare them to, but I don't disagree that they look great. Not so much on inFamous but...that's just my opinion. Uncharted games, Heavy Rain...yeah they look great. The PS3 is capable of producing better quality games. The system specs alone say that. How much better? Debatable. Suffice to say, not enough to sell more PS3s...
I think over time as the devs (more specifically, 1st party devs) have become more familiar with the PS3's tech, they've been able to do some pretty cool stuff in order to pull off some very nice visuals - off loading work that would normally be done with the GPU to the CPU, changing how certain tasks are done etc. Killzone 2/3 did some very nice things with lighting and particle effects, GoWIII also had very nice lighting and some very impressive AA, Uncharted just overall looked great and had a nice hand painted, almost water colour looking quality.
When this gen is basically over and done with, I wouldn't mind seeing someone like Digital Foundry giving a break of which game pulled off the best technical achievements, I think that might be pretty interesting. I know they basically strip down each new title to see what the game engine is doing, so I don't think an end of gen comparison would be too much for them, they'd just have to compare the data they've already got.
"It would be the stupid comment about the a-bombs that the US dropped on Japan that is offensive."
IMO multiplatform games tend to look the same on 360 and PS3, often running a bit better on 360 (especially Bethesda games), and look/run best on a good PC. Generally, PS3 exclusives have better graphics, but I must say Halo 4 is quite sexy looking.