What OS to use on a server

[neptuneshaun]

I am being given a old server from work to have a play with. They are still using Windows server 2003, but apparently microsoft have stopped all relevent updates for this, so would anyone be able t oreccomend either 2003 / 2008, but a breif description as to why they would choose that one please

Also going to be looking at Unix on the second HDD (but keeping that idea out my head for now)