Windows - The operating system preferred by the technologically illiterate. Most of what Microsoft brings to the table has been stolen from other sources, such as Linux. Heavily proprietary OS. You have to depend on MS to fix things because of this. Security is a joke on here as well.
Mac - The hipster OS. Overpriced computers with overpriced software. Built on top of Unix. Buy this one if you want to show others that you can pointlessly spend money (Status symbol). Heavily proprietary. If it isn't Apple approved, you probably can't run it on your computer. You must depend on Apple to fix problems. More secure than Microsoft, but not without its own flaws.
Linux - Designed for people who know how to do more than press the power button on the front of their case. Completely open source. Fixes for problems (including security) come out faster on this OS than any other thanks to GNU. The sky is the limit on things you are able to do with this OS. The only real downside is limited compatibility with some proprietary applications and games. Excellent OS for efficiency and speed. There are some systems running Linux that have been up over 20 years. Mac and MS could never in their wildest dreams come close to competing with that kind of stability.
This is all just my opinion of course, so take it for what it is. I don't claim to be any kind of expert.
:p
