Well, since you're forcing me to talk about myself, I guess I could oblige.
Sirius Black here, Incontestable Wonder Boy of Hogwarts and Slightly Less Than Official Winner of Hogwarts' Most Talented (and Handsome) Student Prize for 1972-1975.
No surprises there, naturally.
What am I good at? Oh, name anything and you know that I'm probably better at it than you: Quidditch, Charms, Transfiguration, hexing Snivellus, Defense Against the Dark Arts, receiving detentions, bagging out Peter, stuffing my face, being handsome, sleeping, plotting with James, being a Gryffindor, annoying Regulus...