[deafbybeheading]

To me, a turning point in my feelings on UX was reading Alan Cooper's "The Inmates are Running the Asylum" [1]. It's a little anti-engineer (he argues that engineers cannot do this right and you always need dedicated UX people), but he explains core interaction design principles very well.

E.g., he draws a distinction between mere UI design and interaction design: UI design is just layering another abstraction (the interface in question) on the underlying software architecture, whereas interaction design starts with what the user wants to accomplish, and adapts the underlying pieces to enable that.

Note that this is not a UI book, or even really all that much of a UX book, but it does make a great argument for the importance of user interaction.

[1]: http://dl.acm.org/citation.cfm?id=553473