I've done my research and i've discovered there's only 6 Operating Systems that I would ever need to use.

For your workstations

  • At the office: Windows
    • I would choose this in almost all businesses as often they require the ability to run windows based applications.
    • In many business environments windows is required to be a client on their network, meaning you are unable to use their network if you are using Linux or a Mac based system.
  • The developer: Ubuntu Linux (free)
    • I would choose this for developers as it’s quick, stable and allows you easy interfacing with developer tools and services running on Linux based systems.
    • This platform can also be ideal for the future of technology due to the fact it is free and that due to the way technology is heading before long all you will need to use your applications is a web browser.
  • The designer: Mac OS X
    • This is a good stable and compatible platform for graphic design applications, ideal for graphics designers.
    • Generally the graphics applications you see on Windows appear on Mac first. This was often the case with Adobe/Macromedia products.

For your servers

  • Web/Mail/Database Server: CentOS
    • Based on Redhat Enterprise Linux (RHEL) this product is designed to deal with the enterprise market offering you real performance, the real difference between CentOS and RHEL is that CentOS is free.
    • The reason why I would choose CentOS is that because it is based on a Redhat product its very compatible with available applications meaning you get them first. It is also very easy to use.
    • Another great aspect of this is that unlike Fedora there’s no product life cycle.
    • The final attribute of CentOS is it’s great community.
  • Game Server: debian
    • I find that the game server applications run best on debian. This is probably the only reason I would use it.
  • IRC/Shell Server: FreeBSD
    • The main reason for this is because its so well received by the IRC community, and offers great compatibility for IRC applications.
    • This OS also offers the ability to use “Jailing”, which was an important aspect before the ability of creating “virtual servers” on Linux existed.

For more information check out the Comparison of operating systems on the Wikipedia