Which operating system is better?

Hi ive been wandering wich operating system is better and why (maybe some statistics/graphs) between well all of them now i know the linux users will say linux and windows for windows but i want to know from scratch ive been using windows xp and its great but i wanted to move to vista but its to slow and xp sp3 is just more advanced but now the windows 7 is out and i see great oppertunities for it is the latest and has the speed of xp and the glamour of vista is this true? and my second part is wich operating system is greatest out of all the choices and why and how (if its not windows) can i run windows programs on it?