Really enjoyed my stay at the 404 hostel. The rooms are huge, with very nice accommodations. Guy who runs the place is helpful, and knows a lot about the area. Its also located very close to a metro stop, so getting there from the train station wasn't a hassle.
A little ways out of the city center, and being so expensive were the only two cons. I had a very good stay, it just cost me far too much, and there aren't a lot of options in Zurich.
Expensive, but one of the only options. Really a good location, very central overall in luxembourg, and quite close to city center.