I have recently become increasingly annoyed with the WYSIWYG editor included with WordPress, at least its current version. Due to various problems it makes it practically impossible to type escaped html markup into a post, which is utterly unacceptable for my needs.
I have however, found I much better solution – PHP Markdown. PHP Markdown disables all the annoying WP auto paragraph functions for plain text editing, and adds its own special plain text markup system which is very similar to that of MediaWiki. It also offers extremely easy code insertion/escaping by simply inserting back-ticks (`) inside of a paragraph, or indenting a line four spaces outside of one.
You can also create headings as easy as
# This makes a heading 1
One other plus is that it does not seem to break past posts that used pure HTML, so you can safely activate it on a blog without utterly destroying all your old posts.
So far I am very pleased with it, and I probably won’t switch to a WYSIWYG editor again anytime soon.