First off, I have to say that I'm not a particularly hardcore fan of anything. But this is a list of some of my favorite stuff:

The Edge Chronicles, by Paul Stewart and Chris Riddell

Most of J.R.R. Tolkien's work

xkcd and other stuff by Randall Munroe

Historical novels by G.A. Henty

Star Wars

Hitchhikers Guide to the Galaxy (the books)

Tintin (the comic books particularly)

And some others that I like a lot, but don't exhibit any fan symptoms:

Old Tom and Jerry cartoons (a lot of the newer ones are trash)

C.S. Lewis' works

Gerald Durrell's autobiographies

Septimus Heap books

Any books I've read by Geoffrey Archer or Jeffrey Archer