Monster Milk

which of the two is better to build more muscle faster monster or muscle milk?
Well I'm not entirely sure what Muscle Milk is, but I do know that it's better for you than Monster. Monster doesn't have any muscle building protein or vitamins; it's simply loaded with sugar and caffeine. In terms of practicality it's worse because if you drink Monster regularly then all of the sugar in it will eventually form into fat and you'll end up putting on the wrong kind of weight. Also, once you hit the sugar crash from prolonged use of Monster, you will always feel less inclined to work out, and your muscles will suffer when you decide that it would be easier to sit on the couch and not wake up for a workout every day.
Not only is Monster ineffective, it's also dangerous for athletes and bodybuilders. The reason for this is that when you drink Monster your blood coagulates (thickens). For a sedentary person this isn't usually a problem. However, when you work out your body needs to pump blood through the veins faster in order to supply your muscle cells with the necessary oxygen to continue your workout. If your blood is thicker than it should be your heart has to work harder to pump the blood through your body. Depending on how hard you're working out, this can easily and quickly cause your heart to fail altogether. Energy drinks and exercise are a dangerous combination which kills more athletes and gym-goers each years than you would think.
So to answer you question in one sentence, Muscle Milk will build muscle much better than Monster without any serious risks.