I tried this out recently as a revision game and it worked out really well - the students seemed to really enjoy it and there was great discussion around answers and arguments of points, as well as some time pressure to get it right like in the exam!
It's based on The Million Pound Drop game - so I grouped tables together and places students in teams of 4. Each team was given 40 sweets each (I got ones with covers on rather than loose sweets!) to start. The game worked well with 6-8 rounds, about half the teams wiped out and one or two would get a few sweets each - you could prepare more questions and make them harder as you go if students haven't lost any sweets after a few rounds!!
So, I labelled the 4 desks A,B,C & D, and gave out the sweets.
I'd put a question on the overhead with 4 possible answers labelled A,B,C & D.
Students have 2-3 minutes to place sweets on the table on their chosen answers (you can decide one table has to be left blank like the show or not)
When the time is up they have to step back from their tables and touch the classroom wall.
Then i'd show the right answer and walk around clearing the sweets that were on the wrong tables back in to a large bag!
Then they return to their tables, a new question goes up and they can spread their remaining sweets out where they want them!
Obviously it would work with anything - you could print out €25,000 notes and give them a million and see which team can win the most money - I found using sweets made it matter more to them as they hated losing them! And the sweets went a long way as they were more likely to lose them than win them over a few rounds.
What's your favourite classroom activity to use?