Hi, and welcome to LQ!
That's a tough call ... usually the "friendly" distro's
are geared towards desktop users ... and since they're
friendly they're commonly chubby.
I'd go with Debian if I were you, the current testing
(sarge) is supposedly going stable, and it has a
much better installer than the older debs.
Slackware if you love full control and don't mind
getting your hands dirty :) for upgrades (no, I don't
trust any of the automated tools for Slack).
SuSE or RedHat servers if you have the bucks