To burn the most calories and fat, aim for multi-joint or compound movements which utilize more than one muscle group at a time
. Good examples of compound movements include squats and lunges, chest presses, chest flys, rows and even deadlifts. These types of movements also provide the perfect stimulus for muscle growth when each set is performed with a weight that pushes to momentary muscle failure. This means pushing each set to the point where you wouldn't be able to do one more rep with good form. Only with enough stimulus will you push your muscles enough to experience results that will change your body from "skinny fat" to lean and defined.