Debian, or Slackware. I prefer the former, but have used the latter quite a bit in the past.
I've found that, in most cases, the more they attempt to elucidate the installation process for RedHat or Mandrake, the bigger pain in the ass it becomes. I guess if you're not wanting to really delve into Linux, then RedHat/Mandrake may be easier, but if you're not wanting to delve into Linux, why are you wanting to run Linux at all?