Reader Question: What are three good “how to” scripts to read?

Three essential scripts for learning the craft.

A question from Lee Jay Iddings:

If you could assign 3 scripts as “how to” scripts, which 3 would you choose?

Lee, I assume by “how to” scripts, you mean screenplays which are not only great stories, but also examples of strong screenwriting practices.

I am tempted to name the very first three I ever read because in addition to Syd Field’s book “Screenplay: The Foundation of Screenwriting”, they were…