From a gaming and community standpoint, absolutely the 360. There's simply far more content.
As an overall value I'd say PS3. It's still the best blu ray player on the market, PSN is free, the games are cheaper and there's actually a decent library now.
They both have their advantages, PS3 has blu-ray and their network is free, AFAIK its got more processing power too, and renders true 1080 instead of the 360s upconverted 720? The 360 has more games and a better network system (but it costs money).
Axing the slim versions, the 360 is much more compact and (IMO) more aesthetically pleasing.
I've got a 360 because a co-worker has one and we sometimes play online. I don't really care one way or the other. I'm sure I would like the PS3 as much if I had one.