I have always loved to take different flavors of Ubuntu for a spin and recently I set up Crunchbang Linux on my Laptop. I'll post a screen shot of my desktop at the end. Aside from being based on Ubuntu the main thing with Crunchbang is that it is heavily based on using lightweight applications. Its main window manager is Openbox, but it also has gtk in there too. Since my laptop is getting older (nearly five years old now) it needs the lightweight applications.
Crunchbang was very easy to set-up. I had zero problems with the install. It is as simple as putting the CD into the drive and letting it boot up to a live environment. Once you are the live environment you can play around with it to see if you like it. If you want to install it you can use the right-click menu to install Crunchbang to your hard drive. I had just installed Windows XP Pro (needed for games/work) on my 60 GB drive. So then I installed Crunchbang after that and it easy dual boots between both. You can find Crunchbang here. The most recent edition is 8.10.2 and it is also the edition that I installed.
If you want something that is not heavy on your system resources or maybe you have an older laptop like mine give Crunchbang a try.
(Desktop photo from interfacelift.com)