I have started using Sandvox by Karelia to build my websites. While it is still in beta (I like living on the edge) I find it very useful. It is well designed as well as aesthetically pleasing, sporting a true WYSIWIG editing of your content.
In addition, its architecture naturally lends itself to extension, both in terms of design as well as components. In fact, I was able to develop a simple "pagelet" with which Amazon Affiliates can easily add product links to their site.