Let's be honest, there's only one name we need to mention here.
1. Joe Morgan (57.9 WAR)
Little Joe wins. He's one of the best Reds of all time, and that's after accumulating almost half of his career WAR on other teams. He's known nowadays as a broadcaster who belongs in the Hall of Lame, but for 8 seasons he was the Reds second baseman. Trivia: In how many of Morgan's 8 seasons did he make the All-Star team?
At his peak, Morgan did it all. He hit for average, he got on base a ton, he had plenty of extra base hits. He played a tremendous defensive 2B, winning 5 Gold Gloves.
He's best known now for winning two MVP awards, in 1975 and 1976 (which weren't bad years for his team, while we're at it). Both of his seasons were amazing, with him hitting .327/.466/.508 in 1975 and .320/.444/.576 in 1976. '75 was better at getting on base, and '76 showed a little more pop to the bat. Asking a Reds fan to pick their favorite Joe Morgan season is like asking a parent to pick their favorite kid.
Joe now works in the Reds front office to the extent that he gets to use the showers at the ballpark, and can be seen in commercials for a car dealership bearing his name that I'm not sure he's ever been to.