I bought Watchmen from October 1989 onwards, when it was first published in 6 issues in my country (I just checked it, as I used to write the purchase date in my comic books). It's one of my most favourite graphic novels until today.
There's one big question to me regarding the Watchmen movie: Will they try to keep the dark atmosphere of the graphic novel (e.g. the disturbing sub-plot "Tales of the Black Freighter")?
Some great recommendations in this thread already, especially Sandman and Maus.
My recommendations for someone who liked Watchmen would be
- Moebius' & Jodorowsky's sensational, lunatic, brutal, humorous science fiction series L'Incal (The Incal)
- Moebius' other works are also highly recommendable, e.g. the comics from his unique series Le Garage Hermétique (The Airtight Garage)
- Electra: Assassin by Frank Miller/Bill Sienkiewicz
- Batman: The Dark Knight Returns by Miller/Janson/Varley
- Samba Bugatti by Griffo/Jean Dufaux (I'm not sure if this was ever published outside Europe)
- Cages by Dave McKean
- Liberty by Frank Miller/Dave Gibbons (if I recall correctly, critics hated it due to its simple story; I liked it)
And for something different, I'd recommend
- Jeff Smith's wonderful series Bone
- the hilarious Donjon (Dungeon) comics from the best of today's European comic artists: Lewis Trondheim (despite his pseudonym he's not from Norway, but from France)
