Chris Evans as Captain America comes to mind. He had played an annoying Human Torch in a terrible Fantastic Four movie prior. No one thought he would become the character so much that it was impossible to re-cast it.
"Joaquin Phoenix playing Johnny Cash in Walk The Line. I am a huge Cash fan and was very disappointed. He absolutely killed it though. I was so wrong."
Chris Evans as Captain America comes to mind. He had played an annoying Human Torch in a terrible Fantastic Four movie prior. No one thought he would become the character so much that it was impossible to re-cast it.