Everyone knows Jeopardy! On the website JeopardyLabs the teacher can use existing Jeopardy boads (as created by other users) or create their own themed board with relevant terms, which will be the answers and matching questions. You can really hone in on one particular area or cover broader subject areas. The class can play in teams where team members take turns. The teacher has to facilitate the jeopardy board and ensure points are assigned to the groups. You may want to organise buzzers.