A big thanks goes to Visualops for the Banner!!
1. The main characters are major science fiction fans, and it's the best depiction of sci-fi fans I've ever seen on TV. I've met people like these, and in some cases, am one of them. (See Sheldon's discorse in Season One on why Superman should't have saved Lois Lane in Superman I.)
2. The premise of a relatively uneducated, but hot, waitress/actress becoming intimately involved with her scientist neighbors qualifies as science fiction...