I've never really been much of a multiplayer user, so I can't answer whether Xbox Live really is better in a worthwhile way compared to the PSN (particularly in a 'costs money' way). And I would definitely have been more for the PS3 before the horribly laggy PSN store update.
...but I'm still going for the PS3. Reliability is a small fact, although neither of the two rival consoles were great at reliability last generation. What the PS3 had that the 360 didn't, was games that really pushed boundaries. The 360 had a lot of really successful shooter exclusives, Fable which was always completely boring to me and then a handful of purchased 3rd party exclusives that the publishers eventually found ways to circumvent (Mass Effect 1, Bioshock).
Whereas the PS3 had games like Little Big Planet, Heavy Rain, Valkyria Chronicles, Journey, The Last of Us, Demons Souls, Afrika, Tokyo Jungle. They might not all be consistently good, but they were trying new ideas and taking chances. But of the thing about taking chances is that sometimes they don't pay off.
To this day, one of the things I regret most about the gaming world is that Quantic Dream (Heavy Rain, Beyond Two Souls) are stuck with David Cage as a writer as well as a developer. Because those games were doing things better than The Walking Dead long before The Walking Dead existed. Heavy Rain gets a lot of stick for it's control scheme, but it's legitimately a work of genius. It's never going to be for everybody and the people looking for a Silent Hill or Civilisation V experience were always going to be disappointed, but never before or since has a game so effectively managed to connect button presses to the emotional feel of doing something. It's really hard to describe, but when you're climbing over a barbed wire fence in Heavy Rain, the button presses feel like the button presses you'd use to climb over a barbed wire fence.
One of my dream games would be Heavy Rain but with The Walking Dead's writing team.
When you combine that with some really solid and incredibly fun games like inFamous 2, Uncharted 2 and Metal Gear Solid 4, you have a winning console.