NBC Sports legend John Madden announced on Thursday that he is retiring. "It's time. I'm 73 years old. My 50th wedding anniversary is this fall," Madden said in a statement. "I have two great sons and their families and my five grandchildren are at an age now when they know when I'm home and, more importantly, when I'm not." Madden NFL Football, Madden's video game, is the No. 1 selling sports video game of all-time. (Photo: WENN)