I couldnt get into the original star trek, it just a little too cheesy for me, a victim of the technology of when it was made (of course, the beaming up effect is still pretty neat). I actually liked ST:TNG for a while but I sorta fell out of love with it before it ended. I never really gave any of the other STs a chance, but I did enjoy the recent movie.
As far as Star Wars..... I think the thing with Star Wars is the idea of Star Wars is awesome. Force powers, light sabers, speeders, and all that ---steaming pile of meadow muffin---, its just so cool. But the execution isnt as great as the concept. I like the original trilogy, I dont love it, I dont think its the greatest thing ever, but its very entertaining. The prequels, meh, the biggest strike against them, other than Hayden Christensens "acting", is that you already knew how it was going to end the first time you watched it.