ad 'warp drives'
For some reason I get slightly annoyed when people bring this up in discussions about space and spaceflight. The reason is that I find it silly to talk about this as if it was around the corner while in reality we haven't even left the Earth-Moon system yet. Or in other words, it is as if Columbus was talking about an expedition to Mars while trying to persuade the Spanish royals to fund his insane voyage to India.
I feel it damages the credibility of the space-fan community (as if it wasn't low already). FTL is totally out of question for centuries to come. People may try making it work on whiteboards by conjuring up exotic forms of matter with negative mass in the same way I may write a fantasy short story, and that's fine. Just don't bring it up while trying to sell space to the people