Why do we use Debian? I think Debian is one of the most stable Linux distributions available. And it's so easy to install packages on Debian. Anyone can do "apt-get install gtypist". What's so difficult? I think, if you don't want pure Debian, you can always try Knoppix.
We have every PC working on Debian (except one which is on Windows ... I really don't know why :) ). We are basically using Debian in a small cluster of eight nodes for running MPI applications using MPICH. Most of the things work out of the box.