You can say:

1. Which HP book is your fav, and why.
2. What other books you like
3. Which HP movie is your fav.
4. What you like to do in your free time
5. Who you think should be a couple (Ex. Harry and Luna)
6. And basically anything else you want to say, besides you personal info.

Please use your username as the subject line.

UPDATE: Any opinions about Movies and Books belong in the forums for those topics. Please do not hijack introduction threads.