I think the two series might appeal to slightly different groups (both geeky of course). Star Trek to me is about futuristic exploration, so it pulls people who have wanderlust/want to get away, see the world, have adventures, and of course find hot alien women. Star Wars feels more aimed towards a history, medieval kind of geek, even though it's based in the future. They made a knight/samurai movie for the future. And of course the Force, which I think most people want because it gives them power. Ironically, that thirst for power leads to the Dark Side. (takes a deep breath and forces the geekiness back down)

The new Star Trek movies was pretty good though.