For which film did Colin Firth win the Oscar for Best Actor?

Who won the Oscar for Best Actor for 'Milk'? Who won the Oscar for Best Actor for 'Crazy Heart'? For which film did Jeff Bridges win the Oscar for Best Actor? Who won the Oscar for Best Actor for 'The King's Speech'? Who won the Oscar for Best Actor for 'The Artist'? For which film did Jean Dujardin win the Oscar for Best Actor? Who won the Oscar for Best Actor for 'Lincoln'? Who won the Oscar for Best Actor for 'Dallas Buyers Club'?