Just something to think about, enjoyable quizzes give most teams reasonable scores so don't make it too hard or people just lose interest. Having read some of the suggestions, they are creative and interesting but how many people would know the answer? One way of avoiding the too difficult quiz is to give possible answers, it gives everyone a chance to contribute even if it's just having a guess by process of elimination ie some of the answers are obviously wrong. Really clever quizzes are the absolute death to most people.