What is the best flavor of Whey Protein?

I'm 17 and really skinny and for the past couple months I've lifted weights on and off, but now that I have a membership to a real gym I'm going to lift more, but I also need to take a protein shake, because I need to gain weight. I can't just eat more, because I have a small stomache anyways and I get full easily. I've tried the chocolate flavored Max Gain protein shake and I couldn't drink it, because it tasted so bad and was always chalky. What do you think is the best flavor and mixes with the liquid best?