Roger Federer has beaten Andy Roddick in a grand slam final on four different occasions.
Year 2004
Wimbledon: Roger Federer defeat Andy Roddick 4-6, 7-5, 7-6(3), 6-4.
Year 2005
Wimbledon: Roger Federer defeat Andy Roddick 6-2, 7-6(2), 6-4.
Year 2006
US Open: Roger Federer defeat Andy Roddick 6-2, 4-6, 7-5, 6-1
Year 2009
Wimbledon: Roger Federer defeat Andy Roddick 4-6, 7-6(6), 7-6(5), 3-6, 16-14
Another cool fact is that from 2004 to 2006 US Open, every match between these two players was in the final round of a tournament. Which of course, Roger won all six of those final meetings.