Christoph Waltz is the clear favorite to win Best Supporting Actor for Django Unchained. Personally, I think every role he is in is memorable, even Chudnofsky in the Green Hornet.
Quentin Tarantino again win an award for Best Screenplay after winning for Pulp Fiction, which is fitting as I have mentioned before that the film is an homage to his previous films.
I'd mention Daniel Day-Lewis and Adele, but really? Do I have to?