@CWO:
Star Trek. I’ve seen every episode of every television series (including the animated one), plus all the movies, and I have lots of reference books on the fictional Trek universe and on the production history of the franchise. I like Star Wars too, but differently and somewhat to a lesser degree. I’ve seen all six of the films – I loved the original trilogy, but I have mixed feelings about the prequels (a point on which I’m probably not alone) – but I only have a couple of reference works on the subject. Compared with the Star Trek universe, the Star Wars universe has more elements that border on fantasy (the quasi-magical concept of the Force being perhaps the most prominent example), and my preference is for science-fiction that’s a bit more realistic in its approach.
One thing both franchises have in common from my viewpoint is that I have almost no interest in the spin-off stuff: the novels, the video games and so forth. For example, I saw some of the early Clone Wars cartoons but they didn’t interest me. This is one reason why I hope that the forthcoming new Star War film (which I definitely plan to see) won’t depend too much on the materials that were developed for the Star Wars Expanded Universe (if that’s the correct name) because if that’s the case I’ll be hopelessly lost.
First: Clone Wars isn’t a spinoff. Sadly, it’s the real thing (and it sucked).
Second, Star Wars has a lot of really good material in the expanded universe. If you never read Timothy Zahn’s Heir to the Empire trilogy, you should start there.
Fun fact: Timothy Zahn was the first to use Coruscant as the name of the capital planet.