I've been using Crunchbang Linux on my Laptop for sometime now and it's my new favorite distro. It's based off of Ubuntu but uses a pre-configured openbox as the window manager. Let me emphasize pre-configured openbox.
If you have ever used openbox, you will know that it is very minimalistic, but very customizable and powerful window manager. Customizing openbox can take some time when you are beginning from scratch, but can have a very personalize desktop. Crunchbang does most of the work for you and includes the tools to tweak openbox all you want. Time saved.
Since Crunchbang is based on you Ubuntu, you have a huge repository of software to draw upon. It has a very light weight and clean fell to it. Here are a few screenshots to wet your whistle.
Give Cruchbang (#!) a try.