I originally posted this as a reply in a screenwriting forum, but it’s pretty relevant here.
When I bought my first LaserWriter printer (probably 1993), I freaked out because Courier was suddenly ghastly thin. On my old StyleWriter inkjet, it had looked properly typewriter-like, but coming out of the laser printer, it was a shadow of its former self.
It bothered me enough that I used Fontographer to pull the Type 1 Courier outlines from the printer, then chunk-ify them a bit and save them as a Type 3 font, which I called Dorphic. (I have no idea why I picked that name, but it seemed to fit.)
So for many years, I happily used Dorphic on all my scripts. GO, for example, was in Dorphic. I would probably still be using that face, but the shift to OS X made Type 3 fonts impossible. I scoured the net for new options, and settled on Courier Ragged, which I used for a year or two.
But a new problem came up. Up until about 2003, when I needed to turn in a script to a producer or studio executive, I would print it out and call for a messenger. I could be certain the script would look right, because I was printing it myself. But once executives (and their assistants) became more internet-savvy, it made a lot more sense to turn in scripts in .pdf form. So, while I could use Courier Ragged, there was no guarantee it would look right when they printed it out.
All of which leads me back full-circle to plain old Courier. Of the natural alternatives (Courier New, or Courier Final Draft), it’s the best-looking to me, both on-screen and printed.
A side-note: Before I became a screenwriter, I made a meager living in graphic design. So the cruelest irony is that I’ve now spent a decade using nothing but 12-pt Courier, or its imitators.