Jack Dawson (Titanic)
Titanic’s director, James Cameron, considered Matthew McConaughey for his film. But the actor wasn’t impressed with the plot and refused. Cameron gave McConaughey a second chance, but the actor didn’t even answer the call. So the second candidate, Leonardo DiCaprio, made a legend out of this hero.
By the way, Christian Bale and Macaulay Culkin also tried to get this part.