I like to use a monospaced font for my early drafts (as well as for
writing poetry and songs). I find it more suited to spotting
mistakes. The main criteria is that it simply looks good. Well
spaced, punctuation large and easy to differentiate, and a look more
similar to book text (with serifs, of course). Italic and bold
versions are nice but not essential — the ones generated by the
computer are good enough for drafting. These are the ones I’ve used
and generally liked:
Linux Libertine Mono
is the most book-like of my monospaced fonts. No bolds nor italics.
Spacing is good and punctuation shows up well enough (though not as
obviously as with some other fonts). Pretty much my main choice at
this time.
BitStream’s
Prestige BT has italics and bolds. Somewhat book-like, though it is
more a typewriter font. Everything shows up well.
Century Schoolbook
Mono is more book-like than most. No bolds nor italics. I used this a lot at one point.
Incidentally, when I don’t draft with a monospaced typeface,
Century Schoolbook is my usual choice.
These two I don’t
like quite as well but could do an adequate job:
Go Mono has italics
and bolds. Reasonably book-like slab serif but feels a little too
bunched up.
Courier Prime has
italics and bolds. A much better and meatier Courier than what comes
with most computers, but still has the typewriter look — not much
like book text.
I’ve found one
fault or another with everything else I’ve tested. That doesn’t
mean I won’t keep my eyes open for something new.