Taxi

An easy ride day or night
Word to the wise: Remises – or radio taxes – look like normal cars, but as they agree a fare beforehand you're less likely to get ripped off. Your hotel or restaurant can order a remise for you.

Taxis in Buenos Aires are certainly the most convenient way to travel, although significantly more expensive than they were just a few years ago, they do not offer the super cheap service they once did. Flag the black and yellow cars down from almost anywhere in the city, day or night, and the competent drivers can expertly negotiate their way through the city's traffic. The red sign 'Libre' means available.
Taxis are usually safe and reliable, just make sure your driver uses a Taxímetro - metre - and they give you the correct change in real bills: some have been reported to give out false bills. They are tetchy about giving out change for large bills anyway, so if you have the correct money, you'll have a happier taxi driver.