TinyMCE. Remove unneeded files for languages which you don't use and it should be lean - way leaner than FCKEditor!
FCKeditor just gave us trouble and more trouble.
And in Tiny you can intercept the "paste" actions and apply the cleanFromWord function. Can't remember exactly how but I managed to do that using some help in their forums. So you can end with a nice semi clean version, you just need to finish the cleaning process in your server if you want to add more complex rules. It's up to you.
In mi opinion forcing the user to learn bbcode or textile or whatever just makes them like not willing to use the system. Specially non tech savvy people. Let's make them life easier
