Are you kidding? Courier, Courier New, and Final Draft Courier are awesome. Each letter is the same width. Got a lot of mileage out of that for college term papers at times, and speaking as someone who reads a shit ton of scripts every day, it's not all that bad.
I use Courier New for everything I write so I guess that one is my favorite.
Courier New is my fave as well because it's the font used on UNIX terminals. Of course I don't use word processors, so the only time I express myself with it is in my blog.