Mark Sloan: 138 episodes (season 2-9, 17)
Fans heard about Mark before we saw him, but we were all wondering: How could he possibly have been better than Derek “McDreamy” Shepherd and led Addison to cheat?
The answer: Mark Sloan, aka McSteamy, was hilarious, sexy, charming, and definitely had that bad-boy-with-a-heart-of-gold thing going for him. He started off as a womanizing, shallow plastic surgeon who had no interest in teaching interns, but he ended his life (he died due to complications from the plane crash) as a dedicated father, soulmate to Lexie, and had one of the most endearing mentor/mentee relationships with Jackson, aka “The Plastics Posse.”
Derek even forgave him for sleeping with his wife, and they resumed their friendship.
McSteamy returned in season 17 alongside Lexie on the death beach, and discussed with Meredith how he checks in on the lives of Callie, Arizona, and their daughter Sofia. Plus, fans of “Slexie” were finally given closure that the two were together in the afterlife.