For which film did Kevin Spacey win the Oscar for Best Actor?

Who won the Oscar for Best Actor for 'As Good as It Gets'? Who won the Oscar for Best Actor for 'Life Is Beautiful'? For which film did Roberto Benigni win the Oscar for Best Actor? Who won the Oscar for Best Actor for 'American Beauty'? Who won the Oscar for Best Actor for 'Gladiator'? For which film did Russell Crowe win the Oscar for Best Actor? Who won the Oscar for Best Actor for 'Training Day'? For which film did Denzel Washington win the Oscar for Best Actor?