Ed D. Wood Jr. is my hero.
Wood did what he loved any way he could. He may have died a penniless drunk but he was more of a success than he could have ever imagined.
There a so many great directors that I cannot list them all.
This site lists them better than I could.
Though I think most of our current directors wouldn't be in the biz if they weren't inspired by the likes of Cecil B. Demille and Frank Cappra.