I like AStyle.

http://www.athlab.com/

I have an idea.

Let's make a WYSIWYG XHTML/CSS editor, that designs its layouts in CSS. It should probably have image-slicing features like ImageReady/Fireworks.

I'm up for it, any takers?

it would be hard because you would have to incorperate the box model for different browsers. It would be millions of lines of code because you have opera and mozilla reading css about the same on one side (the proper way) then you have ie reading it with some quirks and then ie5 reading it totally butchered, then you have the mac browsers konquer, just tons of situations and platforms. Then you have to make the layouts fluid (well I would). I just think it would be a lot of work to my it wysiwyg, No substitute to learning it yourself. But if you get it working I will put it to the test for you :P I am running ie 4 5 5.5 and 6 side by side right now so I can help you debug it. I don't have the time to help code stuff though.
As far as editors go I use dreamweaver for everything right now, not the wysiwyg stuff obviously but I love its intellitext and auto complete, it is excellent for asp.net