Windows is the better OS and this is why: it can run on a HUG variety of hardware.
That’s it. There is no more.
Macs aren’t better at multimedia because they run on OSX; they are better because better multimedia software was made for OSX. Windows isn’t just “good for games”, but more games are designed to run on Windows.
There is VERY LITTLE that a Windows PC cannot do, however. It might not be as easy as on a Mac, but it can be done. The fact is that you CAN’T play Crysis on OSX because A) the highend hardware is not supported and 
the software is not there.