I just finished the penultimate volume of Joe Hill's and Gabriel Rodriguez's "Locke & Key"—"Clockworks".
I haven't been this emotionally invested in or moved by a comic since I read "Moonshadow" in high school. It is bloody, brilliant, brutal and quite simply an astounding feat of writing and illustration; it elevates the comic/graphic novel to entirely new levels. You don't read it, you experience it. I can't recommend it enough.
My local comic book shop is sold out of the last volume, so I'll have to wait a bit (I try to buy from them as much as possible).