Lately, Americans have been learning to once again embrace classic cocktails and cocktail methodology. I'd say that this isn't an isolated fad, but rather one branch of the gastro revolution that has been going on in this country for the past decade or so. The whole "foodie" thing came on the heels of celebrity chefs who introduced our couch-dwelling civilization to the beauty of truly good cuisine, which of course increased interest in wine as well. Combined with the coming-of-age of several American wine regions (Central California and the more verdant parts of Oregon, for example), America's new love of elevated tastes was excellently timed. Wine snobbery begat the microbew boom, which itself begat the very recent micro-distillery boom and the cocktail culture that goes hand in hand with it. This lasting trend of evolving American palates leads me to believe that we're in a good state to start embracing brandy as a culture. As always, appreciation starts with education. Here's what you need to know about brandy as a neophyte.
Brandy, which comes from the Dutch term brandewijn, meaning "burnt wine", is traditionally distilled grape spirit. It's one of the oldest varieties of distilled drinking alcohol in the world, existing in some form since the Roman Republic but formalized some time in the 1100's in multiple cultures around the world. By distilling wine and leaving it to age in a cask, the liquor takes on a distinct flavor profile resulting from the breakdown of certain aromatic chemicals in the grape juice, making the final product turn out more like whiskey than wine.
There are loads of brandy varieties based on everything from grape species to region to distillation method, so there's no single "brandy" flavor. There are good starting points, though.
On every bottle of brandy, you'll find a carwreck of letter that indicate age and overall quality. There's AC (aged for 2 years), VS (aged 3 years), VSOP (aged 5 years) and XO (either really good stuff or merely aged 6 years, depending on where it's from). It should be noted that brandy with the letter salad can still be blended, which means you're getting a mix of brandies from different casks and of different ages, only given one official rating. Single-cask brandies enjoy a simple vintage date like wine, while those extra-nice, crazy-expensive bottles you see once in a blue moon get the Hors d'Age label, which is the fancy, French way of saying, "This is at least 10 years old, but we don't know exactly how old, and it's really damn good".
To be honest, these distinctions don't mean much of anything outside of Cognac and Armagnac brandy because those are the only two varieties that have an official regulatory system. Brandy is versatile stuff, so it's less about what's "good" and more about what you want to do with it. A good sipping brandy may be subtler and more expensive than the average bottle, but it would also be wasted on cocktails. If you plan on mixing a Brandy Alexander or deglazing a pan for a rich brandy sauce, try not to spend more than $15 or $20 on a bottle.
As for the aforementioned Cognac and Armagnac, they are true beauties as sipping brandies. Named for their respective regions in France, Cognac and Armagnac are excellent luxury drinks. The former is distilled twice in copper pot stills while the latter is distilled once in column stills. Both are aged in barrels of local wood. The differences are subtle but not superficial. Armagnac is the result of an older, less refined process, so the resulting flavor is less clean but more complex. Cognac has a nice burn to it, though. Both benefit from being served in a wide glass at just below room temperature. This allows the full aroma to be a part of each sip and keeps the brandy from warming too much from the drinker's hand, which can result in an overly sharp nose.
There are a lot of other kinds of brandy, including flavorful fruit brandy and international pomace brandies, like the ever-more-popular Italian Grappa. Enthusiasts can spend a lifetime collecting bottles and there's enough variety on the brandy spectrum to keep things interesting for dabblers.