We stayed in Rome three nights at the Bed and Breakfast, I Tetti Di Roma. My review on TripAdvisor.com is here. We couldn't get a good rate on a regular hotel, the convent hotels didn't seem to be returning faxes so we picked this bed and breakfast which is one of two rooms carved out of an 8th floor apartement. It qualifies as a find because the price was very low for Rome from what we could find and the room was comfortable. The location was convenient to the metro and felt safe and residential with a couple of places to eat, a grocery store, and most important Gelati.
We spent our limited time in Rome at the Vatican Museums, the Colosseum, Roman Forum, the Parthenon. Of course we went by the Spanish steps and the Trevi fountain. Since we used those metro stops, we saw both multiple times. I wasn't dissappointed in the restored Sistine chapel. I hadn't seen it since the colors were brought out.
We went back to the airport at the end of our stay in Rome to pick up the car we rented from Sixti car rental. We got a Smart car on an internet rate that was better than any other rate we could find in Italy. We loved that Smart car! Small is a virtue on the narrow Italian roads, especially the roads winding through Umbrian hill towns! Sixti's 5 Euro a day rate is a bit deceptive because it is limited mileage and things you normally need like an extra driver and even cleaning the car are extra. But check them out here because its still a good deal even though it really costs more than they are touting.
At the end of our trip, we stayed in Fiumicino one night. We stayed at the Euro House Fiumicino (my review here) . Staying in the town of Fiumicino is a convenient alternative to going all the way into Rome when you are just making a connection to somewhere else. We were coming in from Sicily and leaving for the states the next day, so it didn't make sense to go into the city. There is an airport Hilton conveniently connected to the airport, but it was much more expensive than options in Fiumicino.