Hmm, this is a hard one.
Do I go with the one I've read the most, being Hercules?
Or, the book that got me started reading a bunch of twisted, dark, highly entertaining books, which is Choke...
I could geek out and pick Agile Web Development with Rails but I won't.
Even though I only read it once, my senior year of high school, I think I'll go with Crime & Punishment. I had my thinking cap on for quite a long time, which helped me expand my critical thinking beyond the level I had known.
Bailey, go for it!