Hey there, sorry for the late reply!
"the antiheros of Watchmen and V for Vendetta really intrigued me."
Good for you, these are two of the best graphic novels around. Alan Moore is a fantastic writer, and you usually can't go wrong with him, though from what you've said, you may not like From Hell due to the B+W art and sexual violence, and if you're not a fan of classic characters, Top 10 may be too 'geeky' for you. Otherwise, he's always insightful.

Speaking for myself, I would suggest:
Acme Novelty Library 19 by Chris Ware. A very cool, very famous artist-writer. This is Very adult material, not because it's explicit, but because he deals with the dark side of being a normal person. This initially appears to be a sci-fi story, but don't be fooled. Very sad indeed.

Planetary series (3 volumes so far, the final volume coming soon) by Warren Ellis and David Cassady. It's a very modern take on the arc