Though I guess my first impression of Firefly wasn't much better. I saw the little preview commercials on Fox and thought it was like a Jossed up version of Babylon 5 or something. I didn't even get the space western feel from their previews. Even the train job didn't totally sell me. If it weren't for kicking a guy through the engine I would have been pretty "meh" on the whole thing. Given some time though Firefly showed it's real depth.
So, I guess I'm not the best first impression person. I'll stick with my wait and see strategy.