Crunchbang Linux
If you’re not so into the direction that Ubuntu is taking these days and you like minimal window managers like OpenBox/FluxBox/BlackBox, I really recommend checking out Crunchbang.
I’ve used a lot of different distributions, and have never used such a well-thought through distribution that works as well out of the box (and isn’t super-bloated).
I’ve used it on my Thinkpad for about a year (with a brief foray into ArchBang) and am continually pleased with the choices of packages / configurations they include as default. Check it out if you want a good (and perdy) Linux machine set up sitting on OpenBox and Debian.