Omnimover, excellent taste in books! OK, let's get into this. I am really impressed with your reading of Watchmen 4 times! I especially admire that each reading has meant something different to you, not many books have that magic. I read Watchmen as well and enjoyed it. Need another reading of it actually. Will you see the movie? I loved V for Vendetta from Moore and love this League of Extraordinary Gentlemen books. Have you read the third one yet? I bought it but haven't read it yet. What of From Hell?
I'm kind of in the same boat as you are with Sandman. Gaiman is a great writer, yet I can't really absorb the material as much as I like. 1602 however was a fun read.
Y The Last Man is such an excellent book. I got hooked after the first trade, love it. I highly recommend the Starman Omnibus by James Robinson, which tells the story of Jack Knight, who reluctantly becomes the Starman after his brother, who inherits it from his father, dies in duty. It's a great read, and a completely differnt look at super hero books. I'm enjoying this book imensely.
Kingdom Come is genius, and let's not forget the beautiful artwork by Alex Ross either! Have you read Marvels? It came out before Kingdom Come, has the same art by Ross, and is just beautiful. Great look at the Marvel heroes. (The author slips my mind right now, Busiek?) Also Ruins is good, which takes a different look at Marvel heroes and what their lives would be like in real life. Well worth looking into.
Another great book is Arrowsmith, which tells the story of World War 1, but with a fantasy twist, where dragons and trolls and magic are part of our everyday world.
Maus also is an amazing read. It's an important book, not just for comic fans, but for everyone. I can recommend some more trades if you are interested in reading some other stuff.