I know this is just supposed to be our quick, no-thinking list - but the link @Andre Navarro put up reminded me of something about Glenn Fabry: it's the hands. Yeah, it's all good, but the hands on his characters are incredible. They speak volumes.
In terms of actual artists: Marko Djurdjevic, Frank Quitely, Dave Johnson, Esad Ribic and Kaare Andrews (Astonishing X-Men was as.
But: I really want better graphic design in my comics. There are so many instances of great art being plagued by horrible logos and barcodes (seriously, they can't throw them in the corner of the back page ad?) and it's makes me kinda sad.
I've been looking into Chip Kidd's work (Dark Knight Returns/Year One collection covers, Final Crisis) has really left me wanting more. Even if he can be a bit repetitive at times, at least it looks professional. Am I right in saying that lettering studios are usually responsible for this end of things in mainstream comics? I'm a big graphic design enthusiast/hobbyist and the vast majority of comics design (including recap/credits pages) are diabolical. Hickman seems to be having a positive input on his series' design work, Morning Glories has a nice, polished look, who else is doing good work in this regard?