The apartment we stayed in via Carini , by the market was a very comfortable one, clean, just by the market to do our shopping and surprisingly not noisy. We loved it.
Maurizio and his wife met us by Porta Carini, explained to us where to park for no pay and showed us all we needed to know about the apartment. I recommend this place also because it is centrally located, close to Teatro Massimo, archaeological museum, walking distance to the cathedral, I Quattro Canti (four corners) etc.