Transportation

Nobody ever asks for the second best...

Hi run,

There are a few choices to go from FCO to Termini.

• An official white, Rome taxi, fixed rate (48€). Worth it if you have a group traveling.

• The Leonardo Express (not too good if you have a lot or real heavy luggage, but the most inexpensive) If your hotel is far from Termini, you may have to cab it or take a bus close to your hotel. Or, if your hotel is in Rome and close to some metro stops, then the train would make sense too.

Of course I don't know your logistics. Going to hotel? Going on to another city from Termini?

• Share shuttle http://www.airportshuttlexpress.com/ (This is the one I have taken RT twice) (adjacent to the train station inside FCO airport) They are very good. But, "it may" take a bit longer to get to your hotel. For me, each time, it was about 40 minutes from FCO, but I stay near Termini.
  

This TripAdvisor post has a great outline of various ways to get from the Rome airport to Termini central station. You can choose according to your definition of "best." (It's a couple of years old, so you may want to verify details.)

https://www.tripadvisor.com/Travel-g187791-c144716/Rome:Italy:To.And.From.Fiumicino.Airport.Fco.html

My preferred option: the Leonardo Express train, a direct service to Termini in 32 minutes for €14 per person. The outline also provides options for cheaper buses and shuttles.

https://leonardo-express.com/

For folks staying in Trastevere, the least expensive option is probably the regional train to Tiburtina Station followed by walking, a tram, or a short taxi ride. That train takes 48 minutes and--at least during busy periods--departs four times per hour.

What does "best" mean to you ?