In my professional opinion, “none.” Unless you have some special needs/requirements (and I would recommend that you go see a licensed nutrition professional and your physician to determine your needs BEFORE taking anything), food is generally the best for most people.
I agree 100% with LaRue. There is money to be made in supplements, which is one reason they are heavily marketed. Your physician or other health professional, and a certified nutritionist (one who does NOT make money selling or recommending supplements) are definitely going to provide you the best advice.
I do not take or recommend a pill after a workout and second the advice of LaRue and Ariadne.
While creatine is not a pill form, there are empirical studies that show it helps with energy, recovery and muscle mass pre workout. Here is one study.