@ Scott: That is a great list. Local Hero is classic. One might add:

Fuck Buddies (in production as Friends with Benefits 2011)
Lethal Weapon
Marathon Man

You know what category I'd like to see script recommendations for? Spec scripts. More specifically, true spec scripts, meaning scripts written by people who were not established screenwriters and who had few if any industry connections, yet were compelling enough to sell and be produced.

It's great reading Coen brothers scripts, and Akiva and Koepp, and so on, and I do feel like I learn some things by reading them, but at this point the Coen brothers could write a script with crayons and use Egyptian hieroglyphs for their scene descriptions and still be guaranteed a greenlight.

I think it would be nice to have a list of screenplays sold by previously unknown writers, so I can read them and say, ah, so this is the type of quality I need to shoot for if I’m going to make people take notice.

(Examples off the top of my head: Juno, Little Miss Sunshine, Gran Torino, American Beauty, Sling Blade, Arlington Road – all written, I believe, by people with only minor industry experience or none at all.)

I personnaly think that 500 days of summer is very underated film.
its really can be the modern annie hall.
fantastic..

I'd add Election.

And I second Walter's suggestion. There's more to learn from real specs

LETHAL WEAPON (Any Shane Black really)
BALLS OUT
ETERNAL SUNSHINE OF THE SPOTLESS MIND
BUFFY THE VAMPIRE SLAYER
HEATHERS
THE HURT LOCKER
TERMINATOR
SCREAM

These all have distinct styles in varying genres.

NETWORK

Can't believe I left this off. Talk about dripping with a writer's style.

Kyle Ward's Fiasco Heights, currently in production. It's ballin'.

I think that any of the Cohen Brother's scripts are fascinating reads. It's clear that they take liberties with standard script formatting and style since they know they will be shooting it.

The Kaufman goodies....

Eternal Sunshine
Being John Malkovich
Adaptation

Alex Garland's Sunshine

Network

The Truman Show