The Best Way To Get Around Delhi, India

The famous Red Fort
Delhi is a giant city, with a population of nearly 17 million people, it's the second largest in India (behind Mumbai), and the 8th largest in the world. Public transportation is mediocre at best, although it was significantly improved for the 2010 Commonwealth Games. Traffic is as you'd expect for a city of 17 million, congested. So, as a tourist, whats the best way to get around Delhi for a reasonable price, in a reasonable amount of time?