Big Booty
Each teen is assigned a number. The first person is "big booty" and then the teens number off, with the person on "big booty's" left being number one. All teens stand up and alternate clapping their hands once with hitting their upper thighs once. They begin to chant "Big booty, big booty, big booty, oh yeah. Big booty..." Then Big Booty calls out one of the teens' numbers in rhythm of the clapping, for instance, number three. The teen who is number three immediately says their number then calls out one more number, for instance, four. Teen number four, says his number and calls out another. This continues until someone messes up, and that person is out. The final person is the next "big booty" and starts the next game.
Mafia
Start with a deck of cards. Take out three aces (those represent the mafia), a king (which represents the sheriff), and a queen (which represents the doctor). Take out additional cards to add up to however many people are playing, minus the narrator. If eight teens are playing, take out three additional number cards, which will represent the townspeople. One person is chosen to be narrator.
The narrator tells everyone to close their eyes and passes one card to each player. He then says to wake up and they look at their cards, not telling others what they have. He says "go to sleep" and says "Mafia, open your eyes." The players with the aces open their eyes and silently agree upon and point out one person to be the "victim." The narrator says, "Mafia go to sleep, doctor wake up." The person with the "doctor" card chooses one person he thinks is the victim to "save." Narrator tells the doctor to go to sleep.
Narrator tells everyone to open their eyes and tells who is the victim. The doctor gets to say who he healed. If he chose the intended "victim" the person is fine. If the doctor didn't save the victim, the victim is out of the game. The sheriff then has to guess one person he thinks is mafia. If he's right, that member of mafia is also out. If he's wrong, that player stays in. The rounds continue until all mafia members are called out. Once all three mafia members are out, redistribute cards to start again.
Telephone
Everyone is seated in a circle. One person starts the game by whispering a sentence into the ear of the person sitting next to them. That person whispers to the person on their far side. This continues until the sentence makes the full circle to each person. The last person shares what they heard. It's usually something totally different from what the first person said.