I wanted a modern computer, so AmigaOS was out of the question. That does not change the fact that AmigsOS is awesome.
I wanted to assemble my own computer, so MacOS was out of the question. MacOS was an excellent OS the last time i tried it.
I use my PC to play online games, so Windows was selected because of performance reasons. That does not change the fact that there are several powerful and capable *NIX'es on the market, and that those can reach a high software compatability using WINE.
In the end it's about what the system is to be used for.
