All of the mainstream distros are good (Mandrake, Suse, Debian, Redhat, Fedora, etc). There are a zillion and different people like different things. The differences are mostly what they install, how easy it is to install, what hardware they recognize, and how easy it is to update.
I recommended Fedora because the install is easy. You put in the CD, reboot, and answer a bunch of questions. It is all gui, and you don't really have to know linux to get the system up and running. The difference between Fedora and Redhat is that the Fedora project is sponsered by Redhat, but it is made up entirely of free software, and supported by the open-source community. While Redhat is aimed more at the business market, is not completely free, and they charge for support.
The other advantages of Fedora are that there are a lot of existing bianary rpms for Fedora/Redhat, so if you don't feel like compiling from source it makes installs easier, and the Redhat engineers do work on it, so it recognizes a lot of hardware out of the box and they update it regularly.