I just started reading through Volume 2 of the Guardians comics (from 2008) and it's pretty damn good. It is extremely cosmic-y and tough to follow at times but overall very good. It is definitely more adult than many comics and can be really funny at times.
I am interested who will voice Rocket Raccoon. People throw around Jason Statham and that would work for me but who knows. At first I was skeptical about Rocket but after reading a number of the comics, he is hilarious. He is a drunk smartass that carries lots of big guns.