Ok so you tried mandriva for about 12 hours and decided you didn't like it. Just out of curiosity, what exactly didn't you like?
I always recommend mandriva to starters. If you don't like it I would recommend
ubuntu. You can find good help in the
ubuntuguide.
Remember, there is no big difference in the distros other than packages available, packetmanager and window manager. So if you like KDE then i recommend mandriva, if you like gnome, then i recommend ubuntu. Either way you also have gnome in mandriva and Kubuntu (KDE).
good luck in your search for a suitable distro.