Rafael's is the most technically difficult volley of the three. By the time Cisse hits the ball, it's only really moving downwards, not across or towards him. It drops onto his foot, making it as easy to catch cleanly as a moving ball can be.
Rafael hit a ball moving fast towards him, requiring him to time his strike that much more perfectly. Not only did his shot move much faster than Cisse's, he also effectively had to cancel out the ball's 'away from goal' momentum, so he was putting a huge amount more power into his strike. And obviously the more power you hit the ball with, the more difficult it is to control.
On top of that, Cisse hit a dipper, and Rafael's shot flew straight. The former is easier to produce, because it allows the foot to move on the ball during the contact. Whereas Rafael's contact with the ball had to be perfectly consistent, otherwise it would have sliced off wildly. At the sort of speed he hit it, a modern football is like a table-tennis ball - to make it fly true that fast with no spin is insanely difficult.
Here endeth the essay on why the Manchester United player done good more than the non-Manchester United player done good.