I remember the first time I read Heinlein's The Number of the Beast, I was blown away by it, and thought it was fantastic.  I picked it up the other day while I was out, and was looking forward to reading it again.  Unfortunately, it's about the only Heinlein book that I didn't enjoy reading the second time.  The situations were contrived, the dialog was horrible, and none of the main characters were even remotely sympathetic.  Oh well, The Moon Is a Harsh Mistress still rocks.

(I was in the sci-fi section because I was getting Ender's Game for Eric.  I think he's about old enough)