There are a lot of people who may argue about which type of milk is better. Soy milk is normally used by vegetarians and vegans who do not want to consume any product that comes from animals. Dairy milk obviously comes from cows. Soy contains a good source of protein and calcium.
There are some people who prefer almond milk over soy milk though when they are using a milk alternative because soy contains sugar and carbohydrates that they say, may contribute to fat. People will always have different beliefs about this depending on the diet that they are trying to follow. The milk that you choose will be completely up to you.