i am a newbie so my knowledge is quite limited!!
but still ....
i have used FEDORA CORE 3 and i have found it quite satisfactory. Also i have used knoppix and ubuntu live cd. and i am currently using MANDRIVA 2005
heres my preference..
1=MANDRIVA
2=FEDORA CORE
3=KNOPPIX
4=RED HAT AND SUSE
5=UBUNTU
i havent quite used redhat and suse(only tried them for a quite a short while)
and i am not quite impressed with ubuntu(dont really know why!!)
so there you go dude!! mandriva is my top choice!!! best of luck!! c ya!!!