Brock Lesnar
His first run in the WWE was short, but Brock Lesnar is responsible for a great amount of Smackdown’s success in the early years. Following the brand split, it was Brock who brought the WWE Championship to Smackdown full-time. His programs with The Undertaker, Eddie Guerrero, John Cena, The Rock and Big Show were must-see television.
Over the years, Smackdown established itself as second-rate programming, due in no small part to the combination of the brands and a lack of roster depth. But when Brock was king of the Blue Brand, they were able to produce Smackdown-only PPV events that you had to see. Shows that were, by and large, more interesting than what RAW was doing week-to-week.
I think the title of UFC Champion and his most recent WWE run against John Cena and Triple H will go down as the most memorable periods of his career, but it was the first few years on Smackdown that established him as the “next big thing”.