Maybe the best leg exercise you can do if you had to pick one is the 360' Lunge. I have this exercise within almost every session when Personal Training here in Battersea.
It has numerous variations from pauses, to adding weights and inserting jumps. Like any leg exercise it is important ensure no pain is felt in the joints (knees/back). If so a simple prehab routine needs to be followed until it can be done without pain.