Malcom Clarke Duncan as John Coffey. NOBODY else could have pulled off that role.
And try to image anyone else as House but Hugh Laurie. Which is strange, because he was a British song-and-dance comedy prior to the role.
It’s still mind boggling to watch Laurie in Blackadder or Jeeves and Wooster, even though I saw him in these roles before I ever saw him in House.
I have a lot of issues with Harry Potter casting, especially Sirius and Lupin (Sirius was supposed to be drop-dead gorgeous, and he did not have a porn-stache!
However, that said, Alan Rickman was perfect for Snape.
Also, Johnny Depp as Captain Jack Sparrow.
Gene Wilder as Willy Wonka.
And I’ll second Robert Downey Jr. as Tony Stark.
You know who my Tony Stark would have been? Tom Skerritt. Looks a lot like the Marvel with his mustache. And he looks like he’s about to have a cardiac arrest, which is perfect.
I was going to say Tom Cruise.
That said, think back to how Tommy Lee Jones deservedly won the Academy Award for his role in THE FUGITIVE, and make sure to fondly recall how he delivered any and all of your favorite lines. And now – swap in Samuel L. Jackson.
Maybe not right for the thread, since it’s a past role not a future one, but I caught “Jerry Maguire” on TV the other night and had forgotten how absolutely fantastic Cuba Gooding, Jr was as Rod Tidwell.
But then Iron Man wouldn’t have been a superhero, he’d have been an action figure. 
Jeremy Brett as Sherlock Holmes
Colin Firth as Fitzwilliam Darcy
Alec Guinness as Colonel Nicholson (second choice after Charles Laughton turned down the role!)
(I think I mentioned this one in the earlier thread, too lazy to check)
Kevin Costner was perfect as Alex in The Big Chill.
Has anyone else ever seen the… 1998, I think? miniseries about Merlin, with Sam Neill? I thought Miranda Richardson was absolutely brilliant as the evil fairy queen, Mab. When I heard about this new Sleeping Beauty film being made, I thought, damn, Miranda Richardson would awesome as Maleficent. And it turns out she’s actually in the movie… but as Maleficent’s aunt. We’ll see how that works out.
Oh, Kate Mulgrew made a fantastic evil fairy/witch/whatever the hell Flemeth is in Dragon Age too. She’d be great as Maleficent. But we got Angelina Jolie. Sigh.
Does anyone doubt that Barack Obama will be portrayed by Will Smith?
OMG I can’t wait, srsly.
I LOVE the Merlin miniseries so much, I wore out the VHS tapes. Martin Short was pretty good in it, too. I think everyone was good.
…and he’d have been called LRon Man
Now I don’t
Powers Booth won an Emmy for his portrayal of Jim Jones. Absolute perfection.
Remember when they made a big-screen version of BEWITCHED without Jim Carrey as the one true Durwood?
I still don’t understand how that happened.