I have two servers in my closet (both remotely controlled, so I never go in there )
Intel P2 Celeron 540MHz
1 40GB splitted in 2 partitions, first with NTFS, and some 10GB FAT32(a game that refused to run on NTFS)
OpenSA (a bundled package of Apache, mysql, php, ssl etc. Unfortunately seems to be dead nowadays)
Primary use: Dedicated Multiplayer server for carsims. Web part going down when I find time to move those last few things over to my webserver
Dual P2 Celeron 300a @ 450MHz (50% overclocked, stable, no extra cooling needed, lol)
~40GB in hdds (2 drives IIRC )
Debian, Woody (the stable version)
Primary use: Web and local fileserver.
I used Redhat on my linux server at the beginning, but the computer started to lock up (or be very occupied with something), so I got tired of it eventually, and de-installed Redhat, and installed the Stable Debain package instead, and I have never ever had the same problems.