I am an avid LAN gamer, and as a result have started a small organization in my area. Our games are too large to be hosted of the box someone is playing on, and therefore we are using a PII 450 system as a dedicated server. My question is what OS would you put on your game server and why?

I recently tested MS server 2003(which is still installed on the server), I found I liked a bunch of the networking specific features build into an actual server platform to be something quite desireable(I have been using regular windows builds in the past). However, MS server 2003 disables DirectX so I am facing that I either have to put on another platform, or figure out how to get DirectX to run. Does anyone have any recommendations of DirectX emulators that they have liked?