Win 8 / Metro style which is only great for Windows 8 touchscreen devices, nothing else.
Strange, I don't have a touch screen yet I have both Windows 8.1 and avast! 2014 Free - Pro and IS
All of these work very well even without a touch screen.
Actually, avast! 2014 works in the background so, outside of the occasional VPS update notifications, I don't even know it's there.