San Francisco Giants: Buster Posey
Madison Bumgarner put the Giants on his back and carried them to their third World Series championship in five years in 2014, but the country's most notorious dirt biker still takes a back seat to his backstop as San Francisco's biggest star. Not only has Posey been a staple of all three title teams, he's collected NL Rookie of the Year and MVP awards, a batting title and four All-Star selections. The face of the Giants hardly looks a day over 22—the age at which he arrived in the majors back in 2009—but he actually reached his 30th birthday a week before Opening Day. He's in the midst of a nine-year, $164 million contract and, by the time it ends, he could have an excellent case to wind up in Cooperstown.