What are the transportation options available from Frankfurt am Main Airport to the city center?

The transportation options available from Frankfurt am Main Airport to the city center include trains, buses, taxis, and rental cars. Trains are the most popular and convenient option, with the S-Bahn and regional trains connecting the airport to the city center in about 15-20 minutes. Buses also provide a cost-effective option, with several lines serving different parts of the city. Taxis are readily available outside the airport terminals, but can be more expensive. Rental cars are also an option for those who prefer to drive themselves.