Schweinsteiger is a great player, made the difference for them in the Euros and he had some crackers in the world cup. Klose and Ballack are very good players as well
The only thing ballack can do well is take a volley, he is god awful on chelsea. Best german would probably be klose or podolski (ironic huh, they were both born in poland )
Kevin Kuranyi is by far the worst german player I know (and I know them all)! He only shoots on target if he is 5 meters left or right from that spot he originally wants to shoot from....
At the moment Gomez is only good at his german league team, in the national team he's pretty flat.