Presently the best example I can think of is Hleb. Whenever this guy is in a scoring position, he looks like he's watching some kind of horror movie by the expression in his face. He generally passes and when he shoots he makes mistakes that only 12 year old girls make. Last weekend's miss against Chelsea was just another example of his horrible shooting.
An older player with this problem was Carlos "el Pibe" Valderrama. This guy could be 10 meters in front of goal and he would rather wait 20 seconds for another player to show up and give him an assist than shoot. The funny thing with Valderrama was that he always got his passes right though. So insted of doing a simple tap in from close range, he would do some kind of super chip over 3 defenders that would leave his teammate with a free header. He was definitely some kind of assist king.