The results showed that the secret of a good chat-up line is to encourage someone to talk about themselves in a quirky, fun way. So the best line from the top-rated man was "If you were on Stars In Their Eyes, which celebrity would you be?" On a similar theme, the top-rated female asked "If you were a pizza topping, what would you be?". And what shouldn't you say? One of the least successful lines was "I have a PhD in computing."