Sam Hamm's script is pretty good. The opening scene shows why the Keene Act came about, and also stays true to the comic, except for one little thing. But I'll let you find that out.
SAMM HAMM'S WATCHMEN SCRIPT
My script is basically a direct adaption of the comic. I changed a few things, and left some things out. I focused on the second generation of heroes. The Minutemen existed, but play a very small part in my script, and the relationship between Laurie and her father isn't explored, but I think I stayed true to Alan Moore's vision.
MY WATCHMEN MOVIE SCRIPT