WikiED is a very nice wikitext editor assistant that provides quick access to many useful features. Before reading its benefits, however, please know it only runs on Firefox and requires Greasemonkey. (NOTE: There are now other ways to install WikED, but this option keeps the rich text editor option also available for this site.)
Use and Benefits
This is really one of the niftiest extensions possible.
While not a true WYSIWYG editor, for many users that is actually preferable. WikED provides buttons to add many functions into wikitext similar to how bold or italics works, by simply highlighting the text at hand. Tables, super- and subscripts, etc., are provided; the WikED help page provides details.
Because its action takes place on the client, the choice to use WikED or not does not affect the editing preferences of any other wiki user; this is cool.
The system also has many toggles (see upper-right menu panel) for whether highlighting, the editor itself, etc., shows or not in standard editing mode.
All in all, very nice from an unobtrusive, productivity standard!
If you have a FF browser with Greasemonkey installed, simply click on the first WikiED link in this page and choose "install" at the top of the page. After accepting the install, it will load immediately and then appear as a series of enhancement menus whenever you edit any MediaWiki entry.