Munich's urban humanities are the best among the three universities, but it is expensive and difficult to find a house.
Aachen is a small city, but it is close to the surrounding big cities, such as Cologne and Douste, so the social environment is good and the consumption is moderate, so it is easier to find a house.
Kalu's social environment is not particularly good, but its advantage is that it is located in Baden, and many large machinery and automobile manufacturing enterprises have settled down, which may be helpful for internships or job hunting, with low consumption and unknown housing.