Wouldn't Spock be the oldest TREK character? He's the only hold-over from the original pilot.
"We like the pointy-eared guy, scrap everything else."
Yeah. Up until TNG premiered in 1987, STAR TREK had been the story of Spock. After they destroyed and replaced the Enterprise in the movies, Spock became the only constant across every production. He held that title briefly until "Encounter at Farpoint."