Newsforge points to the perfect Debian setup for ISPs and servers. If you are used to a whizzy Red Hat/Mandrake/SUSE/etc installer, the text-based Debian installer can be a little scary. It can be a little confusing too, but it reminds me of installing Slackware on a shiny new Pentium 60 when I was younger.
The article is an excellent run-through of the Debian install process, with a focus on a functional server without a million things installed by default. Of course everyone thinks of Red Hat as the de-facto server distro, but a Debian server if installed and administered properly can be a lean mean serving machine. Debian can also be kept up to date with security and bug fixes insanely easily. Major bonus there.
The beautiful thing about Debian is that you start with a pretty barebones system, and as soon as you need something, apt-get install it and you’re good to go. You don’t have to deal with all of that unwanted cruft.
Serve on, baby!