Be careful of what you purchase and drink.
Many "Protein Shakes" are "weight gainer" formulas, which is why they include higher percentages of fat. Fat is 9 calories per gram and is the highest caloric payload vs carbs and proteins at 4 calories per gram. Other "protein shakes" are for other purposes and may be higher in other specific nuturients, such as protiens, or fiber, or whatever. The key is to know your "goal" and read the labels of your supplements to be sure you are getting the appropriate nutrients to hit your goals.
Personally, I don't use Muscle Milk....my goals are to keep my current weight or even drop a few more pounds...it has too many calories and too much fat for my goals, so I go with MET-RX RTD 51. The numbers are better for my goals and the flavor, in my opinion, is better than "Pure Protien" or "Isopure" brands...READ LABELS.