I use Debian testing, you could also use Debian stable (2.6.21 kernel or lower). I show how to get a lean mean machine
here in post #5. It's not a large leap from Ubuntu, best part is, is that you can dress it up with what you want it to wear.
My laptop has a Pentium M 2.13Ghz processor, It was way too slow with Linux as host and Windows XP as guest. Plus you have to re-activate Windows as the virtual hardware is not the same as the original. I even pumped up the ram from 1GB to 2GB and it was still cumbersome with that processor. So I go without Vmware on the laptop, I can't have Windows as host because I need Debian to have direct access to the wireless card for street internet.
I tried it both ways on my desktop, once with Debian as host and a few others as guests. Now I go with Windows as host and the rest as guests because it seems to run better/faster this way and I don't have to lie to Microsoft telling them the VM Windows is the only copy installed so I can get my product key transferred to the virtual hardware.