Anything that shows your VALID interest in her. And LISTEN to the answer. Don't just ask things to get her talking to fill time then ask another question. You are not an interviewer. Comment on what her replies are. Ask her about things the two of you have in common. Like, "What did you think about (that certain part) in that movie?" And then REPLY. Even if you don't agree, girls want someone they can have a conversation with. Lord knows we like to talk!
Ask about her hobbies/interest, family, favorite movies and music. Ask about things you have in common. If things go well and you two have some things in common, you'll both be talking about that stuff and not asking too many questions. Just go with the flow of the date.