This is unfinished.
I still like plain text. Almost none of the e-mail that I get that uses HTML formatting actually gains anything from the additional complexity.
Most of my writing doesn't require a 200 mebibyte word processor installation that still can't do reasonable intra-document linking, much less inter-document linking. Moreover, whenever I have to use such a beast, the conceptual overhead always gets in the way. I realize these may just be my own quirks, but they really make a difference to me.
So, I like to do my writing in plain (or very nearly plain) text. But I also like having nicely printed documents, plus some hope of being able to move from the plain text documents to something more sophisticated on those occasions where it is warranted. So, what do I do?
Why both? Well, they both have pluses and minuses.
Pros: I found reStructuredText first. It looks pretty good as plain text, and produces clean HTML and PDF. It can handle deeper structures off the bat than AsciiDoc, which is occasionally important to me. (Some document formats require absurdly deep levels of nested sections.) It can be turned into PDF using LaTeX fairly easily.
Cons: some of the systems I use regularly don't have good packages for docutils, the underlying toolset. This may be in part because although docutils has a long history and is pretty solid, it's still not considered version 1.0 material. I get the surface impression that there are still some things that the developers are thinking about. And there isn't a supported DocBook output format. That's a real shame.
Pros: AsciiDoc, just like reStructuredText, can go straight to HTML. And AsciiDoc's HTML looks nicer straight out of the box.
AsciiDoc is also explicitly a plain-text encoding of DocBook. This lets you be sure you can convert it to something widely used and well understood, which can then be converted by well-known tools into various other formats including PDF and HTML.
It has better package support amongst the environments I use.
Cons: not as pretty looking in source form as reStructuredText.
I wish it was easier to add special purpose structure to both AsciiDoc and reStructuredText that can easily added to all the output formats, for special purpose things like RPG stats or other complicated technical documentation.
So, what do I do when I need something more sophisticated? Use DocBook, of course.