I love science fiction, maybe because I'm a huge nerd, but also because sci fi deals with interesting concepts (social arrangements, trends, technology, etc.) in an extremely accessible way. Sci fi isn't shackled by the requirement of believability, so concepts and ideas can be dealt with explicitly and without subtlety. A lot of sci fi occurs in the future, which makes commentary on contemporary concepts and issues much easier: the reader doesn't have to analyze and speculate on their own about about the impact of current trends or technologies.
Here's a great list of some major works in science fiction, although a few big ones like Dune and Foundation are conspicuously absent.
Note: Unfortunately sci fi isn't known for it's cover art.