And then I decided that I should write down a bunch of random stuff to add to Redking's post, starting with the mysterious exclusion of Jaeger. I'm not going to go into compositions of alcohols that RedKing already covered. I can offer a mostly college-oriented view, which could be a good portion of your customers.
Jaegermeister is a drink
that's apparently ridiculously complicated to make. It is excessively German and tastes like black licorice, so not too many people like the taste, but it also has hardly any of the burn of similar strength alcohols (70 proof) so some people are willing to tolerate a bad taste more than a burn. It's technically a liqueur but most people treat it like a liquor due to its high proof. I've mostly seen people drink it straight, though mixing it with Red Bull creates a jaegerbomb which is popular at colleges (and also not a nice thing to do to your body).
Vodka is the most common party liquor, from my experience. Plain Vodka burns a lot, but otherwise it just has a very neutral flavor that won't really hurt anything it's mixed with besides adding a slight burn to it. This is good because it's easy to just throw in a tub of punch. Vodka is popular both because everyone is typically willing to tolerate it and because it's pretty cheap.
Everclear is a 190 proof vodka that's used when you just want to make something alcoholic for your party hosts to drink. You sure as hell shouldn't be drinking it by itself. Vodka's neutral taste also lets you throw it in basically anything to make a cocktail. Think of any juice and it's probably got a cocktail that's just juice+vodka. Burnette's is a super cheap brand of Vodka (read: popular at colleges), Smirnoff and Absolut are middling in quality/price, and Svedka and Grey Goose are higher end. Grey Goose is something adults buy for fancy parties, and Svedka is more something college kids get when they can afford it to show off.
Bourbon! As a Kentuckian, I'm obligated to be opinionated about my Bourbon because Kentucky is the only state true bourbon can be made (see: Bourbon County, Kentucky). Because of this it's probably not as popular or cheap when you're not near Kentucky, but it still
tastes better than any other whiskey has its fans. It is imbibed similarly to most other types of whiskey, either straight (from a lowball/rocks glass) or on the rocks (with ice in a lowball/rocks glass). Although rum and coke is more popular, whiskeys also mix very well with coke, but most people will only do this with
plain whiskey because mixing your scotch/Irish whiskey/bourbon
means you're a wimp is kind of a waste of the money you spent getting a fancier liquor.
Old Crow is a dirt cheap bourbon, while Jim Beam is more of a moderately priced one. Wild Turkey is on the higher end of middling bourbons and is where you start getting slightly fancy. Maker's Mark is a high-end brand that's popular among adults.
Wine in college is strange. You can get a bottle of crappy wine for $5, and it's not going to be horrible, but most people are going to want something that gives more immediate inebriation. You might see some people purchase
box wines when they don't want to make their own punch, but box wines are generally very shitty. Adults like drinking wines that are actually good, though. Special occasions and whatnot, though some people like drinking it daily as others drink beer.
Gin is another very neutral-tasting drink, similar to Vodka, though typically a little more expensive so not seen as often. Some people really like gin and tonics, though.
Rum has its own dedicated following. It's very rarely sold unflavored, most popularly being sold either spiced (this is the brown stuff, intended for drinking straight) and coconut (clear, intended for mixing). The average rum is going to be 80-95 proof rather than the 70-85 proof that most liquors are, and Bacardi 151 is probably the most popular ridiculously high proof drink. A shot of that is quite the experience. Bacardi 151 is also known for being quite a fire hazard.
Tequila is most often drunk as a shot (with salt and a lime slice, very enjoyable) or in a margarita. Jose Cuervo is one of the most popular brands, and they stock several different brands. Silver is the cheapest, gold is medium, and black is the most expensive. The color depends on the type of barrel the tequila is aged in as well as how long it is aged.
Liquors I've never seen because they aren't really popular among college kids:
Sake: An eastern rice alcohol. I've been told it's good but you're most likely to see this at a restaurant than bought from a liquor store. I'm not sure most liquor stores even sell the stuff. Served hot, and I've been told is an enjoyable drink.
Brandy: Pretty much exclusively a higher class and/or adult alcohol. You drink it from a brandy snifter. Don't ask me why.
Scotch: Fancy whiskey from Scotland. It's never cheap.
Irish Whiskey: Fancy whiskey from Ireland. It's cheaper than scotch, but don't point that out to an Irish whiskey fan.