How do you top a saint? Tim Cook is in a different situation than the other executives on this list because, instead of facing an impossible situation, he's facing impossible expectations as he has succeeded Steve Jobs, the creator of the iPad, iPhone, iPod and iMac over at Apple ( AAPL), as CEO in August. Jobs died on Oct. 5. Apple is one of the most successful companies of the past 20 years, and its stock is one of the most widely held. The 51-year-old Cook has made it clear he's going to go his own way, which is to say he'll probably be more like the traditional CEO and become more of a general manager and administrator than the do-everything, detail-minded Jobs. The outpouring of sympathies for Jobs, all well-deserved, put a halo over his head. Cook won't be able to top that.