A tourist's New York is a city for walking. Streets are ample enough and everything is relatively close. And if not, there's that alternative underground city called the NY Subway. But when the pace of your own legs won't do, and missing the sights on the surface doesn't sound especially alluring, there are two alternatives.
The yellow, checkered cars, the taxis, which are as much of a tourist sight as the Statue of Liberty. Riding them is more thrilling than practical, but this is compensated for by the bus.
New York cabs never rest. Their owner uses them for a few hours, and then the car is subcontracted to immigrants who, in most cases, earn no wages and live off the tips they make.
It also is one of those things where it's hard to not be glad the stereotypes are, more or less, based on truth. See, while the city's cab drivers are as diverse as the population itself, it is not unsafe to say that many of them are immigrants. This is very fortunate for the foreign tourist.
The ride is something you can get from anybody else. But these drivers in particular are a tremendous source of information. So if one is lucky, the driver in question may know very little, or sometimes nothing at all, about the city itself. But in exchange, he can chronicle to the tiniest detail the wedding rituals of Karachi or which crimes result in the death penalty in Nigeria.
These are things that newspapers never pay any attention to. You can read The New York Times and The Economist to learn about the world's state of affairs. But they will never give you the insight a New York cab driver can.
Their driving style epitomizes the city's frantic traffic. It would be an unfair generalization to say that the majority of cab drivers come from countries with few roads and approximative traffic signs. So maybe it has nothing to do with the fact that the New York indigenous driving style bears a striking resemblance to that of the outskirts of Kinshasa. But that's the way it is.
And it is something to consider before taking on the roads of the big Apple. Overall, cab or not, only two rules prevail in the city: any bump measuring over seven feet must be avoided; and any maneuver, no matter how suicidal or absurd, is licit as long as you honk long and loud enough. This partly explains the success of the New York subway.
Those iconic yellow cars tirelessly cavort day and night through the streets of Manhattan. They are moving pieces of living history and thus, deserve at least the same respect respect as the Acropolis in Greece.
Buses in New York are infinitely less practical than taxis. They have their charm, yes, but they also have the habit of fastidiously stopping every two blocks. So you can get practically anywhere in them, which is an important factor, and perhaps more importantly, their safety is unrivaled where New York city public transportation is concerned. But they do consume a lot of patience.
Their inherent safety is why they are the preferred means employed by middle and high school children from any of the five burroughs (this means that, at certain given hours, you can expect to see a significant number of kids from 11 to 17 years old riding next to you). Again, those with less patience should be aware.
However, this option has a lot of virtues for the casual traveler. It is mainly inexpensive (even if you have to connect several buses, which is very likely, to make your way through the grid that is Manhattan, you only have to pay one ticket -- just make sure the driver stamps it in the closest hour), with several options to choose from: a single ticket; a 11-ride Metrocard to which you can add more money when you so need; and two kinds of unlimited ride Metrocards, one that lasts a week and one that lasts a month (costing about 3 times more than the weekly card).
It also has the fascinating option to ride for free if you are below 44 inches tall, which, even if it's not your case, certainly makes for amusing scenes as the authorities and powers that be try to assert a rider's aptitude for this policy.
But a bus' main virtue is the unlimited exercise of the ultimate tourist pleasure: observation. You get to see the city as you ride from one corner to the other. This obviously multiplies the number of hidden, wonderful sites New York has to offer -- it also helps you draw a map of the city in your head and your orientation will increase tenfold.