Willard killing Ben in the 2003 movie. The awesomeness is amped up by the sheer surprise of it. Initially, it seemed that Ben had killed Willard, but that gets subverted loudly at the last possible second.
Cathryn standing up to Miss Leech for being mean to Willard in the 2003 movie. "Shove it up your ass with a big ho ho ho. I quit."