There's hardly anything more nerve-wracking than a first date with someone you don't know very well. It's hard to say whether awkward silence or saying the wrong thing is more embarrassing. Good conversation is the ideal during a first date, but there are a few topics that could send a perfectly good date south. The obvious conversations to avoid are those involving politics or religion, as the old adage goes. Keeping things light and fun is the way to go on the first date. Save whatever strong feelings you have on either end of the political spectrum for a time when you know each other a little better and are more attuned to the other person's thoughts, feelings and ways of expressing himself or herself. A knock-down, drag-out argument about highly charged subjects like these is not the way to ensure a second date. Preferably you'll leave your exes out of the conversation as well - the manner in which you speak of someone you previously dated is a good indicator of how you might behave in a relationship.
If it's negative and hateful talk, then that may turn off your date. The same goes for complaining - if you bitch and moan about everything wrong that you can think of, whether it's the restaurant's service, the terrible movie and the food you ate, then you'll look like a major Debbie Downer. Learning to make the best out of a difficult situation, like not being able to get your waiter's attention, is an attractive quality. Finally, a willingness to commit is admirable - but not on the first date. Leave out your burning desire to get married as soon as possible, if that's the case. It's fine to express interest in seeing him or her again, but commitment-wise, that's as far as you should go on the first date, lest you scare away your date.