I don't know much about architecture, so what I do like about it comes almost entirely from a visual perspective. Over the years, I've come to learn that I really enjoy brutalist architecture -- generally speaking, structures that are made with the raw concrete exposed in some major way. Part of the reason why I think I like this style is because it makes for great urban exploring when these structures go abandoned. I know, weird reason.
Probably more than that though, I think I enjoy brutalist architecture because it always amazes me what designers and architects can do with concrete -- this material that to me just seems mostly hard and rigid and not at all glamorous. I guess I like being surprised.
This Brutal World is a fantastic look at this style. You can pick up this book for $34.