Here you will find the official cocktail list by the international bartenders association. it might be your best shot at defining classics but there’s much discussion to be had. But that’s the fun of it! More on reddit.com

I think if I’ve learned anything it’s that recipes have to be fluid to account and compensate for different flavors. For instance a daiquiri made with Plantation 3 is a really different flavor than one made with Probitas or some local distilled rum that takes like coconuts or whatever. So to say “daiquiri is 2:1:1” without accounting for sugar syrup strength, rum flavor, lime…uh…liminess? Flavor matters too much to stick to a script. So for me, 2:1:1 for a daiquiri is only a way to get started. To have a general sense of the mix. But once you’re on the path, sky’s the limit. More on reddit.com

I disagree with the very idea of having a list of, say, 25 cocktails that everyone should know off the top of their head. That list is fine (despite a few questionable additions- how often do you drink Planter's Punch? or a Brooklyn?), but people who are new enough to mixology that they don't have most of those drinks memorized would be better served by learning basic formulas and patterns. Putting the daiquiri, Jack Rose, whiskey sour, planter's punch, and pisco sour as separate entries is mostly redundant- they're all just sours. And if we're going down that line of reasoning, the Tom Collins and French 75 are just gin sours lengthened with club soda or champagne, respectively, and margarita, sidecar, and cosmo are all in the closely related family of liqueur sours (the mai tai is too, but that one is different enough to be learned separately). You're better off learning how to make a generic sour, then learning how each of those drinks differ from that template. You can also combine the Martinez, the martini, the Manhattan, the Brooklyn, and the Vieux Carre, the Negroni and the boulevardier, and the old fashioned and the sazerac, and in doing so you reduce a list of 25 drinks down to just 9. More on reddit.com

Knowing 3 of these will make you look like royalty at most gatherings. Learn 5 if you want or stick to the basics. Unless you are a bar handle mustached bartender, most wont be needed. More on reddit.com