I stayed at the Hotel Manini, Via N. Torriani 14, 669-0951 (V) 669-3437 (F) and would definitely go back. It cost my wife and I less than $100 US in May (I don't know your dates nor pocketbook). It is about three fairly short blocks from the side of the train station and associated Metro stop. There were several reasonably priced restaurants. However, it was a bit disconcerting to see drug addicts plying their habit in the park adjacent to the Station and hookers near the hotel and restaurant (worse yet, they were _extremely_ ugly hookers). They weren't a threat though.
I am going to embarrass Marco De Angel1, Simona Riela, and their friends again by saying that the GTG with them was the highlight of four trips to Milano--I just don't find it that exciting city. See the Da Vinci (although they don't make it user-friendly to stop in) and go to the Duomo, Galleria, and La Scala, which are a block apart on the Duomo metro stop. If you are there on a Sunday, you might enjoy the flea market (your hotel can tell you how to get there--it's on the imitation river).
Unlike the Italian cities you have visited, Milan succeeds (and succeeds astonishingly well) for its modernity and commerce--not the things a tourist likes to see. We have to go there because most flights that link to the ones here in Dallas leave from Milan Malpensa rather than Rome. You might consider things like day trips as it is a great base. We took one to Lake Como that we really enjoyed. There is vigorous discussion about which lake is best, so you might wish to see more than one. A number of places are also accessible to the South, like the Cinque Terre (which we have not yet seen), or East, like Turin (which we also have not seen, but Simona promises me is worth it and which we will see next time).
Ira H. Bernstein Arlington, Texas