So of all linux distributions that exist, by far my favorite has probably been CrunchBang linux. It is a distribution built on Debian with a wonderful window manager. CrunchBang used OpenBox and created a whole distro that was built around its speed an simplicity. However, as all good things it came to and end. Wanting to replace my slow Ubuntu VM, I went back to the CrunchBang website to see if anyone has picked up the project. No one has, but there has been a few continuation projects that popped up under a new name. Out of all of them, it is BunsenLabs is my favorite. The installation is a breeze and configuration is smooth as butter.
If you are looking for a lightweight linux distro for running as a VM or to run on older hardware, then give BunsenLabs a consideration.