I have used other on-line HTML cleanup tools in the past (especially for including parts of web-pages in a blog post), but so far none beats HTML Washer: [Wayback] HTML cleanup tool & simplifier. For basic & clean HTML 
An online tool that reduces HTML to basic tags and attributes. Removes scripts, CSS, and other non-basic elements like , , etc… Also, corrects errors and formats the HTML doc or a fragment.
–jeroen