Well, there is no "best" Linux.
Like Operating Systems in general, the "best" depends precisely on what it is that you need for it to do.
Mandrake is generally the best overall distribution for workstations and new users.
RedHat has the most commercial support of the distributions, a good packaging system, the most online references for, and is a good mix for workstation and server.
Debian is a completely non-profit organization distribution which focuses on stability at the cost of not being quite as bleeding edge as some of the other distros. It has one of the best packaging systems in terms of .debs, which makes keeping the system current a breeze. It's an excellent choice for the intermediate to advanced users and is popular for servers.
Slackware is the most 'UNIX' of the Linux distributions, and therefore is really for the intermediate to advanced users. It's a very lean and clean distro, and very good for servers.
Those are only the larger distributions. According to my list there are 187 known distribtutions available. Any questions?
