Roger Federer has won 18 Grand Slam titles. The list:2003 - Wimbledon - Mark Philippoussis - 7-6 (7-5), 6-2, 7-6 (7-3)2004 - Australian Open - Marat Safin - 7-6 (7-3), 6-4, 6-22004 - Wimbledon - Andy Roddick - 4-6, 7-5, 7-6 (7-3), 6-42004 - US Open - Lleyton...