Where to live in Paris

Paris is such a big city, it is hard to choose the right neighborhood. It is important to live close to your university to reduce the time spent in the metro. But it is also great if you leave in a beautiful area : for example, the Latin Quarter is really nice but expensive, but the 13th arrondissement is a bit cheaper and very close. People often avoid the north part of Paris. If Paris is too expensive, don't forget you can find great flats in the suburbs. And keep in mind it is hard to get a flat for a student, even more as a foreigner...