I prefer Ubuntu. Windows is a bit slow and pretty unreliable, its performance degrades over time. The update system that demands multiple reboots looks massively stupid. I would say that Windows is probably what drives me off PC gaming. So I use my PC for programming, web browsing, light video/image editing and leave my game to consoles. Of course, I understand if someone uses Windows because he likes it (matter of preference) or if he needs software that's Windows-only.
I really like OS X, but the low C/B of Apple's laptops usually drives me away. I love their build quality, but when you can buy two regular laptops with better specs for that price, quality becomes a moot point since you can change hardware more frequently. So I rather buy a powerful laptop and put Ubuntu on it. I've used other Linux distros before, but settled with Ubuntu since 2008.








