What is the best "protein shake" / workout supplement to take for my body type?

I'm about to be in college, im 6'5'', 185 pounds (so pretty lanky) and fairly active. I workout routinely, and haven't seen much progress towards gaining weight. I want to be hovering around 200-210 come late August. My friends have recommended all of this creatine stuff, but I was leaning more towards Muscle Milk. I basically want to know what is best for my body type at a reasonable price, and more importantly, when the appropriate times to take whichever supplement to be the most beneficial.