Hey, you. Yes, you, dear reader. There's an annual competition in Bilbao, Spain called the Concurso de Feos. There's something about you that makes me think you've got a great chance of winning.
Men and women, old and young, take the stage to contort their faces into the ugliest grimace possible -- and the grosser, the better.
If you watch the competitors closely enough, you can discern some clear trends and classic faces. For example, one of the more popular faces involves rolling one's eyes until only the whites are visible. This is frequently combined with extended tongues or a mouth that is pulled as wide as possible.
You can view a slideshow of contestants at the link.