Durarara!! is the anime of the season, not that it has much competition, but it's damn good. It's from the same people behind Baccano! (even though I've yet to watch that, waiting for a chance to see the english dub sue me), and two episodes in and I'm already hooked.
The story takes place in Ikebukuro, a district of Tokyo. Teenage punks gang up and fight against each other. The gangsters are afraid of an urban legend called "Dullahan", a headless rider, who rides a black motorcycle without head lights or engine sounds. Ryuugamine Mikado is a normal high school boy who seeks peculiar beings. When he moves in to Ikebukuro, a mad scramble for Dullahan's missing head breaks out.
I don't care what the hell you're watching or doing right now, if it hasn't been Durarara!! then fix that.