Start with the basic squats because those help you get your form right. But as you progress, start to incorporate weights to add extra resistance beyond your body weight. This could be holding dumbbells similar to the deadlift, using kettlebells, or using a barbell on your neck.
The benefit of doing weighted squats, especially with the barbell, is that you not only shape your lower body, but you also build a strong back and core as they learn to support the weight. A strong back and core are important for those abs we love so much :)
Try some weights in your squats today, and if you're feeling adventurous, try weights in all your exercises today. Feel the difference, allow yourself to feel a little uncomfortable in the effort.
Cheers Eights & Weights!