This was easier when I was younger and truly loved the classics. Now my taste changes all the time, especially when it comes to "favorites". I prefer easier reading nowadays.
So right now...
Graham Greene- The End of the Affair (i've read all his books)
Vonnegut- Breakfast of Champions (ditto)
Paul Auster- Leviathan (also)
Jules Feiffer- The Man in the Ceiling
(A children's book, but an amazing one. He's mainly a cartoonist, but I still consider him one of my favorite authors.)
Brooks Hansen- The Chess Garden (this is the only book of his that I've read, so it's hard to call him a favorite author, but this one has always been on my top 3 from the moment I read it. I've bought copies for people, and I scour second had stores to make sure I always have more than one copy.)
My first three are fairly common, but I highly recommend that people look for the last two. I'll go a step further- if you read either of the two books and find that you regret your purchase, I'll buy the copies from you. It's difficult to get them here in the Philippines anyway.