An Americano is a shot of espresso with about a cup of really hot water coming out of the coffee machine. I love coffee, and I find Americanos awful. Instead I usually make myself (at home) a "long" espresso, which the French and Québécois regularly drink and call "allongé." It's basically the same quantity of ground coffee as the one used for one shot of espresso, but with more water pushed through it. In other words, the machine is "on" for longer.

Some barristas know about them, but in the USA I've often had to say NOOOOOO! when they were going to add boiling water to it, effectively destroying the coffee's delicate aromas.

I drink coffee without milk or any other "contaminant" and love it that way. It takes much better quality coffee though, because you're really tasting the thing.