Send your teens on a wild and crazy scavenger hunt. Teens have lowered inhibitions, so they'll enjoy searching for and finding fun and random things in your school, house, or neighborhood. To make the game crazy and fun, choose some items that take creativity to find, such as a red plastic baseball bat, or other items that might require the teens to go door to door and ask.
Flashlight tag, or "Ghosts in the Graveyard" or other outdoor nighttime run and chase games, are a throwback to a teenager's younger days. These are fun and crazy games teens can play at night outdoors. Divide them into teams and give each teen a flashlight. They have to tag each other by shining light on each other. You can play freeze versions, where the tagged players have to freeze until a member of their own team unfreezes them, or even a game of "Capture the Flag" at night.
A good, old fashioned fun and crazy game for teens is the standby "Truth or Dare." Teens can ask the "Truth or dare?" question, and others on the team have to choose which one they'll do. Then, they have to answer the question truthfully, or complete the dare. This game can get out of hand, however, as teens might ask questions that go too far, or they may ask others to do dares that are too crazy. However, this game has been around a long time, and teens have been playing it for years.
Send the teens on a photo-collage-finding game. Give each of them a camera, or give each team a camera, and a list of things to take pictures of. Then have a race. Teens will have to race to take pictures of all the things on the list, and then create a photo collage of them. The fun and crazy element comes with the race -- it can get wild when teens are racing around trying to get pictures first.