No. 5: Sherry Magee
Many modern fans may be unfamiliar with Sherry Magee, one of the organization's first true stars. Magee racked up 59.4 WAR and slugged to a 137 OPS+ as a middle-of-the-order mainstay from 1904 to 1914.
He won the 1910 batting title, hitting .331, and also led the National League in RBI four different times. Magee never hit for huge power but still managed a high slugging percentage, thanks in part to very good contact and elite speed. In his career, he stole 441 bases, and his 387 in a Phillies uniform is good for fourth in franchise history. He managed more than 30 doubles eight times during his career.
Magee's banner year was 1910, when he led the league in runs (110), RBI (123), batting average (.331), and OPS (.952). This was before the modern MVP award existed, but Magee likely would've won at least one (he finished seventh for the NL's Chalmers Award, the forerunner of the MVP, in 1914).
Despite his achievements, he's arguably the franchise's greatest player ever to not be included on the Wall of Fame, probably because of how long ago he played.
Primarily a left fielder, Magee's speed and overall athleticism allowed him to notch innings at every position outside of pitcher and catcher. Magee was considered by the Cooperstown Veterans Committee (now the Era Committee) for inclusion in the Hall of Fame in 2008 but did not get the nod. Given how WAR is increasingly shaping the way players are evaluated, and given his dominance within his era, it's possible he'll be considered again in the future.