Windows, Mac, Fedora (RHEL), or Ubuntu (Debian)
Off Topic
Using kubuntu here, works great for programming stuff. Graphic and video editing the options for available software that work consistently leave you wishing you had a mac sometimes.
Only disadvantages I can think of is sometimes there are too many settings, eg: phpstorm has a fullscreen and kubutnu has a fullscreen option for programs. If i turn on the fullscreen via KDE then phpstorm thinks it turned it on, so reverts to it when it starts.
Makes for a juggle:
* turn off fullscreen via phpstorm
* turn on fullscreen via KDE
firefox has its own juggle too for using multiple profiles. and sometimes the developers of KDE add in new features that I dont want without ways to turn them off, so thats slightly annoying. ie
"activities: Just like what you've already got, but buggier!"
For the most part happy with it though.
I did see a macbook pro with a retina display and was soooooooo jealous of the font rendering, its beautiful. But I think thats more of a hardware issue than a software one.