It's always interesting to read the screenplays of the Oscar-nominated films. For writers, I think it's especially useful to read the script first. When you see the film, compare how you imagined it with how it was executed.
The Slate article below features links to the scripts.
Note that some of them are undated drafts while others are final shooting scripts.
Frankly, often earlier versions are better than the shooting script. Sometimes movies suffer from the "too many chefs" effect and lose some of the unique qualities that drew somebody to buy the script in the first place.
