Xfce - Xfce is a lightweight desktop environment for UNIX-like operating systems. It aims to be fast and low on system resources, while still being visually appealing and user friendly.
Cairo Shell - Cairo is a desktop environment for Windows.
LXDE - Why will you like it? Less resource needs. You can use it on your less-pricey embedded board or salvaged computer. Component-based design. Don't want something in LXDE, or you don't want to use LXDE but only part of it?
Talisman Desktop - Talisman Desktop is a configurable Windows shell replacement introduced in 1997 by Lighttek...
KDE Plasma Desktop - Plasma Workspaces is the umbrella term for all graphical environments provided by KDE.
bbLean - Alternative Windows shell