I've done Trek-themed Family Feud a couple of times. It works really well. I didn't have too bad a time thinking up questions (ideally with 1-2 obvious answers and a few more of varying difficulty). The tough part was finding enough people to survey in advance, especially since those people couldn't participate in the game. It's best to do this when you were already planning to attend a con with different people than the ones you are doing the game for, and survey people there (and swear them to secrecy).

It was very time consuming, but people really enjoyed it, so totally worth doing.