South America is not a cheap place to travel around. Following are some tips/suggestions based on my experiences …
Buenos Aires, Argentina (Airport Code: EZE)
I would highly recommend avoiding the pre-paid taxis. It is an utter rip-off. If your baggage is not that heavy or extensive, it is best to use the convenient Tienda Leon buses. It is likely that you will need a walk to your hotel from the main depot near Retiro (near Puerto Madero). Please note that these buses do not stop anywhere you like. Check out the predefined stops on the route.
Within the city, the Buenos Aires Metro is very convenient to use.
Asuncion, Paraguay (Airport Code: ASU)
Unfortunately, Asuncion is not an easy city to navigate in terms of public transit. Luckily, you can explore all the major points of the city on foot, which is what I did.
The taxi rate from the airport is pretty much fixed. You should be able to negotiate a rate of 120000 PYG (Paraguayan Guarani) for the ride from airport to a centrally-located hotel and vice-versa.
Montevideo, Uruguay
Because I wanted to experience the ferry from Buenos Aires to Uruguay, I used the Buquebus ferry service. The Buquebus Terminal in Buenos Aires is at Puerto Madero and easy to get to using Metro (get down at Retiro station). The terminal is quite nicely maintained and has very affordable luggage lockers. I actually left my bigger bag at the terminal and took only my backpack to Uruguay. Though the ferry is not exactly cheap, it is quite reasonable considering the convenience and overall facilities. It is best to purchase the tickets in advance. I bought the to and fro Buquebus ferry tickets on my very 1st day in Buenos Aires. My ferry rides were between Buenos Aires and Colonia del Sacramento. I took bus from Colonia del Sacramento to Montevideo and back. Though there is a snack bar within the ferry, I would recommend against it (overpriced and not that great grub).
Montevideo is quite compact and many of its attractions are located in the city center. For this reason, walking is best way of getting around. The days I were in Montevideo were real rainy days and to be frank, I did not enjoy the downtown area as much as I could have if the damn rains had stayed away.
Montevideo has an extensive bus service. I did not use it as I was staying in the city center itself.
Taxis: Montevideo’s black-and-yellow taxis are all metered. Cabbies carry two official price tables, one effective on weekdays, the other (around 20% higher) used at night between 10pm and 6am, and on Sundays and holidays. I used the taxis a couple of times and they are cheap and convenient.
Lima, Peru (Airport Code: LIM)
Jorge Chávez International Airport is pretty big and quite crowded.
I would highly recommend the Airport Express bus service. Reasonably priced and with a very convenient route. I stayed in the Mira Flores area of Lima and Airport Express is most convenient to this area.
For commute within Lime, especially between Miraflores and Plaza de Armas de Lima (the main square of Lima), I would recommend the Metropolitano Bus Service.
Cusco, Peru (Airport Code: CUZ)
Taxis are the way to go. Please note that you will be swarmed by taxi drivers when you come out of the Alejandro Velasco Astete International Airport. Please remember to negotiate the rate down as much as you can, and enter the taxi only after reaching an agreement on the price with the driver.
Manaus, Brazil (Airport Code: MAO)
Taxis are the way to go. From the Port of Manaus to my hotel, I paid around 30 Reals (for a 5Km ride). The bus service is also quite easy to use. Google Maps are handy for figuring out the bus routes.
Tefe, Brazil (Airport Code: TFF)
Tefe is quite small and walking is the best option. I did see lot of Bike Taxis around, even though I did not use one. The Tefe Port is right in the center-edge of the town.
Rio de Janeiro, Brazil (Airport Code: GIG)
The Galeão Airport is huge! I used BRT No:30 bus, which departs every 30 minutes or so, to get to the nearest Rio Metro stop, Vicente de Carvalho.
Within the city, Metro and BRT are the best way to get around.
Sao Paulo, Brazil (Airport Code: GRU)
São Paulo–Guarulhos International Airport is another massive airport. Provided one does not have too much luggage, one can take a bus from the airport to the nearest Metro station. Tatuape metro station is the one of the nearest Metro stations. Bus lines 257 (Guarulhos Aeroporto Internacional (via Ayrton Senna) and 299 (Guarulhos Aeroporto Internacional (via Assis Ribeiro) can be used to transfer between the Metro station and the airport. The ticket can be bought from the driver and will cost around 4 Reals for one trip.
If you have heavy luggage or if you are arriving at night, the best way to get to a hotel or into the city is a taxi. The best option is the blue-and-white Guarucoop radio taxis from the airport. These taxis provide a flat rate from the Airport (130-150 BRL). They are reliable and generally safe. Guarucoop has a counter at the Arrivals exit.
Foz do Iguaçu, Brazil (Airport Code: IGU)
The yellow bus No: 120 starts from Foz do Iguaçu International Airport and take you to the center of town (roughly 15 kilometers). Each ride costs around 3.20 Reals (BRL). Buses are the easiest way to get around the town.
Getting to Itaipu Dam is easy from the main bus terminal. Inquire at the Tourist Counter (within the bus terminal) and they will point you to the correct bus. Please note that the tickets have to be purchased 1st, before they allow you to enter the bus terminal. You then enter the bus through the door meant for folks who have already purchased their tickets. Once the bus is outside the terminal, one door is used for entry and the other doors are used for exit.
Getting to Argentina and visiting the Argentina Iguazu Falls is quite complicated. One needs to take the colorful buses marked “Argentina” to get into Argentina. Once you complete the Brazil and Argentina border crossings, Rio Uruguay bus needs to be used to get to the Iguazu Park. Ticket can be purchased from the driver. It is best to keep Brazilian Reals and Argentine Pesos handy, as all bus tickets have to purchased with cash. I got lost at several points and wasted 2-3 hours going back and forth and I actually did Brazil-to-Argentina-to-Brazil-to-Argentina crossings within 1 hour! 🙂 Once inside Argentina, I took the wrong bus and got back to Brazil side, instead of going to the Argentina Iguazu Falls Park.
Adios!