The author who has had the most impact on me as a person is Jhonen Vasquez. Once you have come in contact his one of his creations, it will burrow deep into your brain, where it will grow, fester and feed off of your life force until it emerges as a gigantic abomination of God and nature that will destroy and remake the universe into a hell designed especially for you! I have read some stuff by Alan Moore so I have some knowledge about what mainstream comics where at a specific time, the only thing of his I read that I did not like was V for Vendetta, all the characters seemed to be passive-aggressive. I will check out the authors you mentioned. Warn the people about Jhonen Vasquez before his tainted bibliography twists anyone else into a sweaty fanboy!
Watchmen wasn't mentioned.
V for Vendetta wasn't mentioned.
I am dissapointed. Very dissapointed.
For interesting stuff that's chock full of allusions and mystique, I feel Neil Gaiman is a can't miss. The blended stories, retellings of classics, retconning of legends, and the like in The Sandman were wonderful.
Also, if you read Stephen King's Dark Tower series, the comic stories being done right now are excellent. They have phenomenal artwork, and even though they've left the canon behind, it feels like these stories jumped right out of the books.