1st person: Lions or Tigers
next person: Tigers
Beach or mountains?
next person: mountains
hiking or swimming
and so on...
there's no right or wrong answer just your preference the more people participating the better variety of this or that questions...
you choose one then present a different choice that is caving/cave related no explaination needed, this game can be a good one for long road trips to/from caves in a vehicle full of cavers...

to start:
Wet caving or dry caving?