Killer Leg Combo

Weighted lunge. 
Place a barbell behind your back on your shoulders or use dumbbells resting on your shoulders or to the side for added resistance, then step forward into a lunge. The key thing is to make sure your knee does not go past your toe on your front foot. Step back to your original position and repeat with the other leg. This move is great for shaping your quads, hamstrings and butt (glutes).

Plie squat. 
Stand with your feet apart, at a 45-degree angle, holding a dumbbell in your hands. Just like a regular squat, lower your body and try to get your thighs parallel to the ground. This exercise is great for working the inner thighs, in addition to your glutes.

Weighted bridge. 
Lie on your back and dumbbell or weight plate on your stomach, then push through your heels to drive your pelvis up. Lower your pelvis and repeat the motion.

Prisoner jump squat. 
Put your hands behind your head, with elbows out of your perifial vision, squeeze your shoulder blades together, then squat down and explode at the top into a jump. When you land go right into your next squat to absorb the impact before jumping up again. This will get your heart rate up get your calves involved, in addition to working your glutes, legs and core.

For a Killer leg workout do these exercises back to back with a break in between sets. Aim for 3-4 sets. Reps with depend on your fitness level, anywhere between 10-20 reps. Let your body guide you - do as many as you can without compromising your form.