Arnold Schwarzenegger - Terminator.
Homelander - Anthony Starr.
Albert Wesker - Shawn Roberts.
Superman - Henry Calvill.
Jack Sparrow - Johnny Depp.
Neo - Keanu Reeves and Agent Smith - Hugo Weaving.
Iron Man - Robert Downey Jr.
Those actor played their role so well that i don't think I can see them as any other character or any other actor taking their role.