I'm using Debian on my servers, but Ubuntu is a good choice as well. It is a good distribution, but apt is superior to rpm. I got lots of negative feedback from Mandriva users (fanboys?) saying that apt is not needed when you have "such a good tool as urpmi", etc. I also used apt for a SuSE and a Fedora howto, but SuSE/Fedora users didn't like that, too, so I decided to use each distro's original package management tools again. From many years of experience I know that apt is better, but because of such negative feedback I leave it to the users to find it out themselves.