In 1997, "Shrek" was slated to star Chris Farley in the title role. He had done 80-90% of the movie when he died, and the studio decided to replace him with SNL castmate Mike Myers. New footage has just been released featuring some of Farley's readings.

I've actually never seen any of the Shrek movies, but just listening to those voice-overs makes me feel like the Farley version could have been pretty decent.