After whining about the decline of comics for many posts I thought it might be worth mentioning ones that are actually good. I'm going to mainly focus on regular ongoings just because that's easier to keep straight.
Captain America - Ed Brubaker is constantly surprising as he mixes superheroics (mad scientists, superspies, guys who talk to falcons) with more serious concerns such as moral responsibility and the ravages of violence.
Batman, Batman and Robin, Detective Comics, Streets of Gotham - Killing Bruce Wayne turned out to be the shot in the arm this whole corner of the DCU needed. The dynamics of the new Batman and new Robin feel fresh and unpredictable while the side stories in Detective and Streets are just as interesting. I'm not yet as convinced by Gotham City Sirens and haven't gotten around to the other related ones (Red Robin, Batgirl, etc).
Mighty Avengers, New Avengers - Bendis can certainly do wrong but he rarely does in these two. And he's probably the best dialogue writer in all of comics.
Invincible Iron Man - Matt Fraction is writing this as a science fiction political thriller and it feels like he's completely nailed the character.
Jonah Hex - I suspect DC kept this going because of the upcoming movie but it's solid storytelling. We need more Westerns.
Unwritten - I have a feeling this could lose steam the further the story goes but at the moment it's really playing with the possibilities of its premise (a guy whose father wrote a Harry Potter-esque series based on him but finds out much more went on).
House of Mystery - Maybe the way to avoid the notorious low sales of anthology titles is to have a continuing frame story. In this case it's incongrous characters trapped in a mysterious, otherworldly house - exactly the kind of thing I love though I suppose others could be bored. The entire series becomes at some point about the very nature of storytelling.
Fables & Jack of Fables - It was a great idea to make the spin-off book quite different from the original - one somewhat sombre, the other giddy comedy.
Powers - Bendis again but having his own universe lets him get away with stories that could never appear in the regular Marvel world.
the Deadpool books - Yeah yeah I know. Overexposed and three ongoings? But at the moment the mix of black humor (sometimes so black it's not even humor), wild superheroics, clever dialogue and a genuinely insane main character are pretty hard to resist.
the Big Two kids books - The various books that were being published under the Marvel Adventures and Johnny DC lines were aimed fairly young (I'd guess 7 or 8 up to early teens) but for the past couple of years were the most consistently enjoyable being put out. They had that Silver Age feel of invention and pure entertainment without being at all retro. Too bad they're now nearly all cancelled.
Bongo - Yep the Simpsons and Futurama comics are rarely as good as the shows (except for the annual Treehouse of Horror issue) if only because they're not as dense. But they're still usually a hoot and the recent addition of Sergio Aragones pushes them to the top.
There are several others that I mainly read in trades and are about a year or two behind what's currently appearing. These include: Amazing Spider-Man (though it's been uneven since going to the three-times-a-month schedule), Daredevil, The Goon, DMZ, Ex Machina, Irresistible.