Ok, so I primarily run Gentoo on my server and as a linux environment on my desktop. I have done some experimenting in Suse, Mandrake (now Mandriva), Redhat, Xandros, and a little with Ubuntu via a liveCD.
I enjoy linux primarily because it's something to learn and offers such vast possibilities. On my server I run Apache with PHP support, MySQL, ProFTPd, sshd, and Webmin currently. This setup basically allows me to experiment with PHP frontends to databases, host my current POS site, and remote command line access via SSH or remote management of Services/Users/etc with Webmins web interface. Oh, and of course there is FTP available to a few people.
The next thing I would like to do is install and configure Bind, DNS, and a DHCP server to handle my network and use my current router more as a hub and wireless AP. Once this is working I want to experiment with creating a VPN tunnel, for which I will require the assistance of davec for a network to tunnel to. Eventually I would then require VPN connectivity to access FTP, and enable Samba shares so that one could create mapped drives.