Virtually all games we played as kids are fun to do again in youth ministry. Capture the Flag, Sardines, Who Has the Bacon, Tag, Freeze tag (and its endless variations), Ultimate Frisbee, etc become fun again when played as a group in youth ministry. Grab a book from the library, look on line, or just reminisce with the teens. Look for games that can include everyone regardless of athletic talent. If your group is large divide into multiple teams, Capture the Flag with 6 teams instead of 2, or have a tournament with playoff brackets. For an added twist play them in the dark, or indoors, or add bubbles or water. Always add music and snacks, and be sure to take lots of pictures.