I am limited in my options due to requiring x64 support. So far not many shell replacements have offered that.
I gave Emerge Desktop a try, and uh...well. It's light. That's for sure. You can right-click on the desktop to access a menu from which you can access your programs. And that's about it. Not my bag.
I've used LiteStep before...around the time I was using Windows 2000 - which, incidentally, is exactly the version of Windows that LiteStep is running on in the screenshot on their front page. Oh so promising...