5. Leonidas - 300
King Leonidas (Gerard Butler) might have been an awesome soldier, but he wasn't the most thoughtful of gents, as when you spend the majority of your waking day rutting with your hot wife and kicking people down wells, you don't really need to think all that much. Leonidas nevertheless seemed to have his head screwed on when it came to tactics, organising a seemingly impenetrable phalanx formation that the Persians wouldn't be able to break through. He didn't count on one of his own screwing the pooch, though, and it's a consequence of his own stupid actions. The grotesque hunchback Ephialtes comes to Leonidas, keen to redeem himself for the tarnished legacy of his father, but the King, worried that he would do nothing but compromise the phalanx, dismisses him. A dejected Ephialtes then goes to the Persians and helps them to take the Spartans down. If Leonidas had just placated the guy - even by just putting him at the very back, or sticking him in an area where he'd most certainly die - then the Spartans might have been able to hold their ground a little better.