A reader writes to ask:
Quick question: which font do you use when writing a manuscript – Courier New or Courier Final Draft?
Good question, though those two fonts are hardly the only Courier variants available to choose from. One could also try Courier10 BT, Courier Std, Courier Stylus, Dark Courier, and no doubt many others.
But you asked which font I use. It's Courier New, but that's really only because it's the default Courier font that comes with Windows. Courier New prints a bit light and thin for many people's tastes, so if you have Courier Final Draft (which comes included with Final Draft screenwriting software) you're probably better off to use that instead. It's a somewhat heavier and darker font than Courier New, and it looks better printed.
The bottom line, though, is that any member of the Courier font family is probably fine to use.