quick poll
I was just reminded of an academic game in one of David Lodge's books--Small World, maybe?--where all of the teachers admit, in turn, the most important piece of literature they've never read. So here's a question for everyone reading this: what's the book you really, really should've read but haven't?
I'll start: One Hundred Years of Solitude.

Brighton Rock.
Don Quixote, among thousands of others. (I'm not particularly well-read, unfortunately.)
The Odyssey.
This is pretty much the reason I'm back in school, but Ulysses has got to be the most egregious.
Anything by Faulkner except the horrible Sanctuary.
I also find myself thinking (thanks in no small part to reading David Lodge's Consciousness and the Novel) that I need to read some more Henry James (I read Daisy Miller years ago and recall nothing of it).
'to kill a mockingbird.' my high school was so bad it wasn't required reading. most of the brontes books--i only read 'jane eyre' and feel like i'm missing out on much more. i second ulysses, although i could never get into faulkner.
I third "Ulysses"--I gave up on ever reading it once I graduated college and had no teacher to lead me through it. Also, the Bible. Also, a lot more, but once I start naming them I won't stop.
the catcher in the rye. the grapes of wrath. um.
on "mockingbird", i used to get gregory peck mixed up with gregory hines. when i read that for school, consequently, i thought the whole family was black.
All of them.