I say 8.1 only cause that's what I have and how I'm using it.
If you don't know this add-on is $2.99 US. (no I don't work for the
company).

I just noticed that the windows key toggles from desktop to metro menu
(the little tile list of all your apps + the desktop apps, not the
larger icon start menu). And all while keeping the taskbar on the
screen.

I find this really interesting that I can be using modern apps and any
desktop programs pinned to taskbar are also in easy reach. And it lets
you turn off individual windows 8 hot corners.

I haven't used classic start menu or stardocks start8 so I have no basis
of comparison. I only mention this since there seems to be some
interest from some about a win8 menu.