For the "Piss in your pants" award, I give it to the dragon in "Sleeping Beauty". That thing was big, omnimous, and breather green fire. When I first saw it, I cried like a little girly.
For the "Epitome of all Dragons", I award Draco, from "Dragonheart" for two reasons, he was smart, deadly, and clever, and nothing can beat Sean!
My vote goes to Draco/Sean Connery from Dragonheart.
"So instead of calling me Dragon in your language, you will call me Dragon in another..." (or something to that effect... hey it's been awhile since Ive seen it )