Re: Your top 5 DC graphic novels...
None of these are "graphic novels" in the strictest sense, but I'll go with DCU stories that are collected all in one volume.
1. All-Star Superman
2. Superman: Whatever Happened to the Man of Tomorrow?
3. Kingdom Come
4. Batman: Year One
5. Batman: The Long Halloween
Honorable Mentions: Batman: The Killing Joke, Superman: Secret Identity, Superman For All Seasons, Batman: Ego, The New Frontier (it's 2 books if you don't count the absolute edition)
- "As chance would have it, I have won the Pulitzer Prize, and so I am qualified. Speaking in my official capacity as a Pulitzer Prize winner, Mr. Schneider, your movie sucks."--Roger Ebert