The editor I require, needs to be easy to use. Even for people with absolutely no HTML knowledge
The projects I have tried are:
I use the Telerik RadEditor in my CMS. It's VERY robust, and has several hook-in points that allow you to extend its functionality to meet your needs. It doesn't have (afaik) the live view like the one StackOverflow uses, but that could probably be added if you so desired.
It does however provide the photo uploading/arranging functionality you mention, in addition to allowing you to upload documents and some other media. The downside is that the control is quite expensive, close to $1,000 I think. Fortunately, my company covers the cost :)