would like an opinion

At the moment, for one of my classes, I have to list 5 advantages and disadvantages of the following OS:

Fedora
FreeBSD (UNIX core)
MacOS
WinXP
WinVista

I’ve done that, but I now have to choose what I think would be the best OS above to use for:

Corporate Web Server
Home desktop computer
Medium size office network
Media studio

I’m a bit stumped as the above OS are all good for some things but not for other things.
I would like to know others thoughts on this, and why you chose that OS.

Thank you