Heath Ledger would have been great as Jack Dawson (Leo DiCaprio) in
"Titanic" (1997). I know "Titanic" is a really geeky film (otherwise a
blockbuster), and Leo made it about the ship, but this Aussie would have
worked well, maybe opposite Jennifer Connelly.
Now his Batman movie might surpass "Titanic" in sales, but actually Heath and
Leo have a lot in common (if you ignore the fact that Heath is dead). People
have said that Mark Wahlberg was a lot like Leo and that they could have
traded movies, but Mark likes making non-mainstream films, while Heath
and Leo never minded the mainstream as much.
These days new actors are making strange movies, so tracking these 30-something actors proves fruitful. Heath would have been a good Jack Dawson.