Shane Black is a legendary screenwriter. He wrote several classic spec scripts that sold for a lot of money in the late eighties and early nineties like Lethal Weapon and The Last Boyscout. He’s making a come back with the new Iron Man movie, which he wrote and directed.
I read this post recently that was a sort of “best of” Shane Black. I highly recommend reading it: http://www.vulture.com/2013/04/why-iron-man-3s-director-ruled-hollywood.html.
He has a very hip, distinct style that makes his scripts very entertaining to read. While I don’t recommend copying his style, it is worth reading his scripts to get a feel for what a “good read” looks and feels like.