Anonymous Pro: http://www.marksimonson.com/fonts/view/anonymous-pro
Input: http://input.fontbureau.com
Inconsolata: http://www.levien.com/type/myfonts/inconsolata.html
Courier Prime: http://quoteunquoteapps.com/courierprime/
Triplicate: http://practicaltypography.com/triplicate.html

Old but still relevant: http://hivelogic.com/articles/top-10-programming-fonts
Latest trends: http://www.typewolf.com/top-10-monospaced-fonts
In development: http://typophile.com/node/121876

Very helpful, thank you!

I see that none of the examples has tried as hard as IBM did with Bookface Academic, or Diplomat (not available for Selectrics in the U.S., but it was available for U.K. typewriters) to be a monospaced typeface that doesn't look like a monospace typeface.

Of course, trying to make a monospace version of a traditional Roman typeface does run the very strong risk of making a monospace typeface that looks even worse than one that doesn't do that, but IBM in those two examples seems to have managed fairly well.

If you scroll down, you can see a little bit of Diplomat on this page.

Camingo Mono
http://www.janfromm.de/typefaces/camingomono/overview/

Lucas de Groot’s Consolas and The Sans Mono

This page has some Diplomat on it some way down:

http://www.covingtoninnovations.com/michael/blog/1001/

PragmataPro: http://www.fsd.it/fonts/pragmatapro.htm

Before, I used Source Code Pro and then later Input. On my screen, at least, its rendering seems crisper. I know little about font rendering, but perhaps its narrow width with tight curves helps with this. Also, compared to the other two, scanning words is easier yet it is still easy to descern crucial details such as punctuation.