If you're a Batman fan, check out Detective Comics. It's currently being written by former Batman: The Animated Series writer Paul Dini, and his whole run will be a series of done-in-one stories. The first issue just came out (#821) and it was a serious good read.
I'll also reinforce Astonishing X-Men, Runaways, and The Ultimates.
Also, two new creative teams just took over the other x-titles Uncanny X-Men and X-Men. They're fairly easy to jump into, just as long as you know the names of the main characters, but otherwise, are introduced for you.
Uncanny X-Men is starting a space opera arc, and Adjectiveless X-Men is...well, it's hard to say, but really good.
Also check out the recent Captain America trades (Winter Soldier) by Ed Brubaker, and the last five issues of Daredevil (also by Ed Brubaker). Some serious good stuff.