I love writing about the Harry Potter and Dark Angel series since there are just too many avenues to explore. I also enjoy reading the following kinds of fanfics:

1) Alternate Dimension/Time Travel
2) Severitus 
3) With Harry betrayed or sent to Azkaban
4) With pairing as follows: Harry/Luna, Harry/Daphne, Harry/Susan, Harry/Fleur,  Harry/Gabrielle or no pairing at all.
5) Crossover with Naruto, Glee, Dark Angel, X-Men, Batman, Sailormoon, Smallville.

Credit to Alexus Dracius for the Header

Accounts on other fanfiction sites:

http://www.harrypotterfanfiction.com/viewuser.php?showuid=6593

http://fanfiction.net/~darak27