The barbell squat/walking lunge combo is extremely effective for blasting the quads and glutes. And if your main goal is fat loss, you'll find that a lighter version of this superset is incredibly beneficial due to the metabolic demands of stimulating such a large amount of muscle mass at once. In other words, you're gonna really get out of breath, but it'll be worth it!
This squat/lunge superset works by combining two effective compound exercises for the lower body. By combining the two exercises, your quads will be maximally stimulated to the point of momentary muscular failure, thus leading to adaptive benefits. Although these exercises are quad dominant, they still hit the glutes quite well.
This is a superset, meaning you go from squats to lunges with little to no rest between. With the squat, use a weight in your 8-12RM range. For the walking lunge, go with a weight that puts you in the 8-12RM range – as in 8 to 12 steps with each leg. If you're going for more of a conditioning/endurance effect, go up to your 20RM. (Note: I think barbell walking lunges are best, but use dumbbells if that's more gym-friendly for you.)
Form tip: To make sure you hit your glutes hard, use a full ROM (range of motion) on each of these exercises. On the squat, full ROM means you squat to the point where your hip joint is level with your knee joint, or even a tad deeper.
On the walking lunge a full ROM means 1) taking a long enough step so that your knee doesn't go out much beyond your toes in the bottom position and 2) going down to the point just prior to your kneecap on the trailing leg touching the ground, which should put your thigh on the forward leg right about parallel to the ground.