The one that gives you absolute control is Notepad. But if you want a WYSIWYG editor Netscape Communicator is free, and relatively free of proprietary code too.
Serif do their older version of WebPlus free, but the code isn't as 'clean'.
There used to be a stripped version of MS Frontpage 'FP Lite', not sure if it's still around, but again it introduces rogue code.
I'm sure there are alternate options that others will be able to tell you about.
-------------------- TFC 'Going to trial with a lawyer who considers your whole life-style a Crime in Progress is not a happy prospect.' - Hunter S Thompson (1937-2005)
My favorite is Alleycode editor at http://www.alleycode.com/download.htm it is free and will easily switch from wysiwyg to code view. Best of all it comes with its own tutorial, building a site which takes you through html and css. Even if you are proficient with html and css it will have you up and running in no time using the editor.