I started using XFCE when Redhat 5 came out. It was not part of the package, but I was so disappointed with the bloat at the time that I looked for something lighter. Downloaded XFCE and installed it. Never looked back.
There are other very light GUI’s but XFCE is Gnome compliant and works for me.
That is why I use it as well--it works for me, and I don't have to adjust my work methods/styles to work within it.