I read a mixture of stuff, rarely fiction these days though. Anything by Gladwell or the Freakonomics guys I usually buy right away and finish off over a weekend.
Canticle is one I go back to about once a decade. I first read it as a teenager and I've been hooked ever since. I'm not really sure if it's a great book or not, but I like it because it reminds me of my high school days.