Scott Hanselman recently wrote up a list of "Six Essential Language Agnostic Programming Books". That list, including the comments with other suggestions, is certainly worth a look. I have to admit that I haven't read most of what he lists, and only skimmed others.
Instead of trying to add to his list, here I think a little broader than just programming: which books and other media have had an impact on my professional or general productivity?
Inbox Zero I was one of those persons using the inbox as my mailbox, calendar and to-do list. Inbox Zero retaught me the joy of e-mail - by using it less. Highly recommended.
The following books are still unread on my shelf, so I can’t really recommend them yet - but from what I heard, they are quite popular (and I really need to get those for my reader!):