Squats, any kind. So many diff ones
4 sets is plenty. But should mix it up also. Sometimes pyramid up to 5 sets then back down so like 8 to 10 sets. Drop sets also
Squats 4 x 10 to 12
Leg extension 4 x12
Leg curls 4 x 12
Leg press 4 x 10
Weighted Lunges
Calfs. 2 diff exercises 3 to 4 sets each
Thats more like a bodybuilding routine btw