The questions can be about anything and we really have touched on as many topics as you can imagine. As long as we follow the pattern of "What's your favourite?" then anything is fair game. I've learned that by having the kids explain their answers I end up learning a lot more about them, my husband and maybe even myself.
Now the kids like to play it at dinner. I have to admit that at first I was hesitant to play while we eat. I like our dinner conversations. I like to hear what happened in each person's day. I was worried that we'd lose this but now I realise that this simple game has provided me insight into my kids that I might never have gained if we had just kept to our normal routine.
For example, when my son asked "What is your favourite tree that gives fruit?" I was expecting to hear 'apple' or maybe 'peach'. I wasn't expecting my son's answer 'Truffula Trees', which in hindsight I should have expected as he is a HUGE Seuss fan. My daughter's answer to "What is your favourite TV character?" was also well thought out. Her answer; "Laura Ingalls Wilder because she she is a good role model for me because she was good at school and became a teacher."
I still limit the number or rounds we have at a dinner to 3. That means we answer 12 questions in total as we each get to ask one question per round. I still want to hear a little bit about what went on at school.
I highly suggest you try a game of "What's your favourite?" with your kids. It is a great conversation starter and I promise you that their answers will be more than the typical 'fine' you get when you ask "how was school?"