Most will not have a choice or even care that much as new PCs come with it preinstalled in the future.
A good question nonetheless. For my part I am distinctly underwhelmed by what I have seen. My current machine came with XP which was upgraded to Vista on the day of it's release and subsequently had W7 as a clean install on the day of its release. The enthusiasm for W8 has never developed.
Without wishing to provoke yet more discussion about Apple (its a pointless exercise) my thoughts are now turning to an iMac next time. Having resisted the iPhone for some time I now see it as the most important bit of kit I own.