I first read Stardust at a friend's instance and then didn't read anything for a long time until rileysaplank sent me Neverwhere. Then I devoured the rest of his books. What do you think would be a good introductory book?
She's into Stargate SG-1, Firefly and Doctor Who.
Which should be Brother's GF's first Neil Gaiman book?
Ocean at the End of the Lane
The Graveyard Book
Other (in comments)