4. Jay Leno
Most people don't even realise Jay Leno once tried to be a movie star. That portion of his biography is likely just behind the Conan O'Brien controversy in terms of things he'd like the general public to forget about his legacy. Before hosting the most iconic late night talk show in history, Jay Leno had high hopes for his acting career (a recurring theme in this list). Primed to make the leap from relatively unknown comic to movie star, Leno cozied up alongside Pat Morita to play one half of an odd couple in the buddy cop comedy Collision Course. It was a more subdued version of Lethal Weapon (a Harmless Weapon, if you will). But with a burgeoning comedian in the lead role, one would expect the emphasis to be placed on humour over explosions. Audiences didn't buy Leno as the tough guy action star and the movie was a gigantic flop, ensuring the quick death of Leno's film career.