Last year before my Transatlantic cruise on the Liberty, I stayed at the Sunbay Park Hotel in Civitavecchia. It is 40 minutes by car from the airport of Rome and it’s close (5 minutes by taxi) to the port were the Liberty leave’s. You can see the ship when in port. It’s a old but very clean 4* hotel with breathtaking views of the sea and European breakfast is included.
This year I will also be staying in this hotel before and after my cruise. It isn’t Rome but why stay in busy Rome when you can stay in a quiet area.
Hope this is helpful
Cruise History: 1990 Mardi Gras, 1993 Jubilee, 1998 Imagination, 2002 Fantasy, 2003 Carnival Spirit (panama canal), 2004 Carnival Triumph, 2005 Carnival Liberty (transatlantic)
We also sayed in that hotel for the Grand's crossing last November. Nice, clean, and a good breakfast to get you going. Price was right also. IIRC, $100 USD.
We used Airport Shuttle to get us from FCO to the hotel. 140 Euros including 15% tip.
In Rome, we like the Bernini Bristol Hotel.
SS Norway (12 times) '85 - '97; Radiance OS 06/01; Island Princess 11/04, Grand Princess 11/04/05, Golden Princess 7/21/06, Golden Princess 2/24/07, Explorer of the Seas 12/23/07, Island Princess 11/15/08