Bologna

If your budget will allow it, you can't get more central than the Hotel Commercianti, just off the main Piazza: http://commercianti.hotelsbologna.it. I stayed there quite a while ago, but my brother stayed there just a few years ago. We both agreed the hotel was very nice, and the breakfast spread is impressive for anywhere, but particularly for Italy (where breakfasts are not, shall we say, a specialty).

Hotel Metropolitan in the city center.

We've stayed at Albergo delle Drapperie twice - we liked the location and comfort of the room. It's very centrally located.

Albrego Centrale - right is the center of town near the main square. Great place - I would highly recommend it.
Check tripadvisor and venere.com