6. The Imaginarium of Doctor Parnassus
We were all gob-smacked when it transpired that Heath Ledger had died of an accidental drug overdose in January of 2008, and though his role as The Joker in The Dark Knight had been completed, he still had plenty of work to do on Terry Gilliam's fantasy flick The Imaginarium of Doctor Parnassus, having only shot about 1/3 of his total work. Though Gilliam considered abandoning the project, you have to give the guy credit - he picked himself up, and came up with a pretty damn smart way to save the movie and the jobs of everyone working on it. Because of the fantastical nature of the film, Gilliam was able to get away with a lot. Ledger's character Tony travels through a mirror, and throughout the rest of the film, his appearance magically transforms, with him now being played by Johnny Depp, Colin Farrell, and Jude Law (who all donated their salary to Ledger's daughter). Incredibly, Gilliam managed to make a surprisingly entertaining, even coherent adventure despite losing his leading man, and unlike many directors on this list, didn't have to desecrate the actor's memory in the process.