Forum Moderators: bakedjake
Desktop: For ease of use probably Mandrake. Installation is a snap, and doesn't take very long, depending on install options you choose. Mandrake desktops that I've set up seem to be very stable and generally scaling wasn't much of an issue.
Server: Well, I'd defer to FreeBSD for that, but for Linux, I haven't seen anything that tops a Gentoo built server. Can't claim ease-of-use on that one, though, at least for the installation. Once installed, though, it's pretty easy to maintain with the emerge system.
Since it's built literally from the ground up for your system, they tend to be reliable and stable machines.
That said, I've only built small systems that easily handle the load they are given, so I haven't had to worry much about scalability.
Pick any two. :)
The most stable and easy-to-use platform is probably Mandrake. The most stable and scalable is probably one of the RedHat derivatives, as is scalable and easy-to-use.
For all three? If you've never used Linux before, and you don't want to learn the internals, I'd stick with Mandrake.
Mandrake has to be the easiest to use, being very Desktop related.
Redhat has server market in its pocket (so scalable?), my experience is only of the enterpise and I find it great.
Currently I run Debian, for my day-to-day. Gentoo for my development, Mandrake to show to my friends!
PS: 'bestlinux' is now www.sot.com