Sean Connery
Sean Connery played Indiana Jones' Father in the 1989 action flick Indiana Cones and the Last Crusade. Connery didn't return to the role due to bad blood or a bad script; he had simply retired from acting in 2003. Steve Spielberg tried to get him back into the game, but it was no use. Connery said, "It was not that generous a part worth getting back into the harness and go for."
Jamie Lee Curtis
Jamie Lee Curtis is the daughter of the original scream queen Janet Leigh, so it only made sense that her acting debut was in a horror franchise. We all know that there are tons of Halloween movies, and Curtis really only had two in her. She simply wasn't interested in filming a third Halloween film (the fourth in the franchise) because she had other things going on. She did, however, come back for Halloween H20, Halloween: Resurrection, and 2018's Halloween.