Milo Ventimiglia joins This Is Us as Jack, returning to the small screen after stints on Gotham, Chosen, and Heroes. The Gilmore Girls alum, who played Jess Mariano for five years in the early 2000s, got his start in the '90s, making cameos in The Fresh Prince of Bel-Air, She's All That, and Sabrina, the Teenage Witch, before landing his first lead role in 2000's Opposite Sex (pictured above).