As Thief12 says, Windows 8 is designed to be used on a tablet. I just recently bought a new laptop with Windows 8 built in and I couldn't work with it. If you are using it on a desktop pc it's going to be a lot harder to navigate and complete certain tasks than doing it with a touchscreen.
Windows 8 takes a huge step away from the classic pc concept, so if you are fine with that and maybe already using a tablet, just go for it.
If you'll have to do a lot of work-related tasks, then I'd recommend using Windows 7 as it is just more established in companies.