Some time ago i wanted a HTML editor for a small back-end content manager. I wanted one that worked well across all browsers. I did try HTML Area, which worked well but was IE and Moz only. Well i've just come across a flash text/html editor. It has some limitations , like the generated HTML cannot be posted (or so it seems) but you can view the generated code, as well as
Save
Load
Delete
setSize Method
Color Picker
Fixed Font Sorting
It also uses span classes instead of font classes (for true HTML output)
These editors are great but the problem we constantly run into using them is the clients reliance on Microsoft Word and cutting and pasting Word into the text area. Without going through a lot of steps to paste into Notepad or elsewhere to remove the extra fluff - I haven't found anything that will reliably clean that up before inserting it into the DB.
The best way we found out to remove the M$ Word fluff was saving the document as HTML from word. Opening on dreamweaver and using the M$ Word Clean Up command. May be there is one way to autoatize this task.
We use Activedit (IE only) and wrote a function, on paste to strip everything in <> and it works pretty good stripping out Word format and turning it into content as if it had been pasted from Notepad. Here is an example if you want to try it - http://www.k1marketing.com/test/example.cfm - it works everytime when clicking the paste button - and most (but not all) the time when using Ctrl+V to paste.
TinyMCE is one of the best WYSIWYG HTML editors out there. It's free, full of features, and highly customizable. It supports cleaning up text that's been copy and pasted from Word.