Hands down, Squats are one of the best lower body exercises there
are. They are easy to do and can be done with or without weights. You
can move your feet closer or further apart and it will work completely
different areas of your legs.
Another
good exercise is jumping squats. I like to alternate one squat jumping
as high as I can straight up in the air and then on the next repetition
jump forward as far as you can. Repeat this process as many sets of 10
jumps as you can.
Warning: Squats Can Be Hard On Your Knees! The
more weight you use the more punishment your knees will take so be
careful. Start slow, if you have to then start using no weight and
perform the workout slowly and deliberately. Keep the entire movement
under control and do not stress your joints when stopping and changing
directions.