For me it's definitely books that have generic superhero art (not a lot of creative details and generic big boobs and big pecs) and plotting, which remind me so much of the '90's. Really anything that looks like the characters are there only to service a not-terribly-interesting plot is unlikely to grab my interest. And there a lot of books like that.
Also, I'm pretty tired of book where it's our world but there are monsters too ala Hellboy. I love Manifest Destiny, but I nearly never even gave it a look because of the premise.