Hmm... I can't remember if I've ever used mandrake before, but the most user friendly distro from install to boot that I've ever tried was RedHat. I never liked it that much though (I think it teaches bad habits), so I recommend slackware.
Slackware is straightforward, clean and simple from the get go and very much like "traditional" UNIX, so I've always had a soft spot for it
Gentoo is quite easy to work with once you have it installed, but it doesn't really have the simplest installation method unless you follow the documentation to the letter!