The thread title says it all really. What are the really worthwhile computer books to have (and what are the ones to avoid)?

To start things off, for computer hardware Scott Mueller's "Upgrading and Repairing PC's" is my well thumbed bible:

http://www.amazon.com/exec/obidos/tg...books&n=507846

And for Windows XP I like Bott & Siechert's "Windows XP Inside Out" best of all:

http://www.amazon.com/exec/obidos/AS...369647-5260852