So, why does DC do it for me?
My take: right now, the DCU feels more like a genuine superhero community to me. The Marvel Universe... doesn't. And I'm not sure why.
My best guess is that it's because the interactions among characters in the DCU are more varied and complex -- and there are more of them. I can think of fewer deep friendships in the Marvel Universe, or rivalries, among the heroes -- at least, that aren't rooted in the characters all being in one book or having come from one. It's not just that the big DC icons do it better for me these days -- it's that the *subordinates* are so much more interesting, and their interactions with the big guys and each other are more complex. Marvel couldn't do a series like Identity Crisis, because the community aspect that made IC possible simply isn't there. Which is ironic, when you think about it, because a big part of Marvel's early success was its rampant cross-overing within its own titles. But there's not enough of the heroes really relating as people, and I think that's Marvel's weakness as far as its efforts at separating me from my money go.
Rick Jones is a big exception where Marvel's concerned -- he's one of the few characters that relates to a number of different heroes (including Hulk and Captain America) as a friend. The friendship between Spidey and the Human Torch is another. But DC does it better.