Rome to Sorrento

Napoli, but I wouldn't want to drive in the city. Gaeta is an interesting city with a small harbor, beaches, hills.

I'd recommend taking the train. High speed train from rome to Naples and the local train from Naples to Sorrento. You do NOT need a car in Sorrento. The city is best seen on foot, and all the nearby sites- Capri, Almalfi Coast, Pompei, etc. can be done with public transportation - (train, boat, bus, taxi, etc).

I think it is great that you will have a car, as it makes you much less dependent on public transportation. Sometimes you may just find a place where you want to stay for awhile and you can do this if you have a car. We love having a car when we are in Italy, unless we are going only to cities. The area around the Amalfi and south of there is delightful.

Sorrento visit experience can depend on the time of year. For example, jammed in late summer. Do think about your parking plans in Sorrento. We saw long lines of cars at the underground lots every night (I mean, walking to dinner) when we were staying there (May, 2014) without a car. Learn which hours/streets are closed for the Passeggiata each night-separate issue from parking. You will also find Amalfi Coast (AC) parking (and two-lane road traffic) an annoyance, when you use the car for that excursion.

Because we took the fast train, I can't vouch any towns to the North. It is convenient (but not essential) to have a car to visit the Villa d'Este or Hadrian's Villa, both close to Rome. I would have been interested in the historic palace in Casserta. If you are beach nuts, note that there are almost no SAND beaches at your destinations, but there probably are some on the way. Sorrento has mainly swimming platforms in the gulf, because of the cliff topography. The AC beaches are pebbles.

As Chloe mentioned, having a car allows for flexibility. Some towns/sites on the way to Napoli are Anagni (the City of Popes and it's 11th century cathedral, Fumone (a very small dramatic hill town with a fascinating castello, and Monte Cassino ( restored abbey built by St Benedict and site of major WWII battle) to name a few.i

Thank you all! We have a car (came with our package). I was planning on parking it at the hotel when we arrive and use public transportation. I love all the help and recommendation. We are spending 5 nights in Sorrento and 3 in Rome.