What questions will turn a girl on?

If you listen to whatever they are talking about, act interested, and ask questions back that prove you were listening - that will "turn them on" more than anything you're going to talk about.

As to what subjects you can bring up that they'll like:

1. Your future plans with her.

2. How much you love her.

3. How much you enjoy being with her.

4. How many dreams you have that you want her to share with you.

5. What a great time you had with her family last weekend.

You get the idea.