I've had to use Vista, 7 and 8 at the day job. Not keen on any of them.

The laptop I bought about 3 or 4 months ago was Win7. I installed Ubuntu Linux (my preferred OS) alongside it at first in order to give Win7 a fair chance. With the release of Ubuntu 12.10 I have completely ditched Windows again. My wife and I are now Windows-free on our own machines, and I only have to use it occasionally at work.

Windows 8 in the office is still huge, slow and overwhelmingly proprietary. Better than Vista, but still... meh.

I tend to work on my Linux laptop instead of the desktop machine. Free OS, free software, smaller, faster, prettier and more secure than Win. I use my machine for web design, sound and video editing, vector and bitmap graphic design, playing DVDs, Skype... Linux has free applications that do all that and more.

First thing I do on every new computer I get is install Ubuntu. In future I won't even bother trialing whatever Windows version comes with the machine. I'll simply replace it straight away.

Ubuntu.com homepage

YMMV.