Best OS for Gaming Server?

I'm thinking about building a game server, but before I start to go out and price hardware I need to choose which operating system I will be using to I can choose the proper hardware for the OS. I have been leaning towards Linux since it is free and is less of a resource hog than windows, and in 64bit has better support for quad cores and large amounts of memory. I was planning on using it for COD4 or Battlefield 2

Windows Server? or Linux?

Which one is more stable, handles large loads of data, most compatible for hardware and for users using the server...ect?

please give any info possible

thanks

linux would best do. But a little more configuring.........................if you run a server, go with intel ethernet cards. They cost more, but you will be more happy with them. ......................But if your unable to get it going under Linux, you can allways revert back to MS...............But make sure that you have a good upload connection if your going to run a server, or it will be laggy for the end users!