Cognitive psych is ovbiously important to people here, so I want to point out a CogSci book thread over from reddit/r/cogsci.
http://www.reddit.com/r/cogsci/comments/bmbaq/dear_rcogsci_lets_construct_a_musthave_library_of/
I would be interested in an extension of this thread here, since LW has somewhat more computational theory of mind slant.
I mostly got through my classes by reading the textbooks... did you take Physics or Chemistry as an undergraduate?
I had physics and chemistry in high school, plus quite a bit of bioinformatics at university. No textbooks in either case.