Ken Griffey was an exceptional baseball in his own right: All-Star Game MVP (1980), three-time All-Star, and two-time World Series champion.
And here's some perspective: he was an All-Star despite playing on the Big Red Machine, the Cincinnati Reds team that dominated the National League from 1970 to 1979 and included Hall Of Famers Pete Rose (well, former HoFer, but still the MLB's all-time hits leader), Johnny Bench, Joe Morgan and Tony Pérez, and was supported by Dave Concepción, George Foster, and César Gerónimo.
Their starting fielders were known as the Great Eight. With the All-Star Game being what it is and needing to represent all teams, it was difficult to pick more than three players of a single team at once, so the fact that Griffey Sr. made the cut three times was a testament of how good he was.
He will tell you, however, that his greatest achievement was playing alongside his son, Ken Griffey Jr. with the Seattle Mariners in 1990 and 1991, to finish off his career; they were the first father-and-son duo to suit up as teammates. He also claims Junior was the best player he ever played with, and that only the great Willie Mays can compare to him.
Which seems about right, to be honest. Like Barry Bonds, he had it all and made use of all his DNA-given abilities, but unlike Bonds, Junior played clean.
By the age of 25, Junior had already surpassed his old man's career home run total of 152, clearly on his way to the Hall.
Here's a Game-Used Bat card of Ken Griffey Sr.'s, B-KG from Upper Deck's 2001 Decade 1970s set: