Tables and chairs, as a wise man once said, you got a dinette set. No chairs, you got dick.
Now, I am not trying to say that the combination of rum and Coca-Cola is dick. It's not dick. It's easy to make, its components are complementary, its ingredients are found in any well-stocked home, and it is delicious. But it is a half-formed drink, an incomplete grade, a preemie. Put rum and Coke together and you have something utile but predictable, as evidenced by its purely functional name: what you have there is nothin' but a rum and Coke. But add one ingredient, one simple little squeezing of lime juice and you've got something magical. You've got yourself a Cuba Libre.
Rum and coke, you got yourself something your 17-year-old kid brother drinks when he doesn't want to get busted. Cuba libre, you got yourself something that Vito Corleone and Hyman Roth sipped when they were bootlegging in the '30s. (It's a testament to Fredo Corelone's mushy character that he favored the banana daiquiri.) And all it takes is that little jolt of lime that cuts the sweetness of the rum and the soda with an opposing adult element of sour. To make yourself feel even more like a pre-revolutionary Hemingway tough guy (no time for cocktails in Fidel's Cuba, comrades), do what I did: head to your local bodega and pick up some real, hardcore, old-school Mexican Coke -- glass bottles protect the fizz and real sugar gives it that extra kick.
A lot of people will drink a Cuba libre from an old-fashioned glass, with a 1:2 mixture of rum to Co-Cola, but there are often mitigating factors. For me, it's that I'm a thirsty motherfucker, and I live in south Texas where it's 85 degrees out at 9PM. So I go for the taller highball glass with about a 3:1 ratio, so you don't get the nasty edge right away if you're dry enough to guzzle. A lot of people are trying to boutique rum the way they have vodka, but this is the perfect drink for your plain ol' drunkenness-delivery-vector light rum (I used Appleton Estates White). Also, while it's not necessarily a big deal to use other colas, going with Coke really does make a difference -- it's crisper and less sweet than Pepsi and gives you a nice blend with the lime. (Stay away from diet colas, though, which lends an unpleasant chemically aftertaste.)
I didn't have any fresh limes, but I did have some Dream Foods Volcano lime juice, a packaged organic thingamabob from Mexico with lime essential oil in the cap that's incredibly flavorsome and just takes a spit's worth to really liven up a drink. If you're eyeballing the prep, you want to put in just enough Coke that it's brown, but not so much that it's dark. It should have a caramel or light tea look about it, but it'll be eminently gulpable with a hell kick for when you get it all down. This is a pretty great anytime drink, but it's especially great in the summer or when you're outdoors: stir one up, and viva la revolucion, motherfucker.
The Recipe: 2 1/2 oz. light rum; pinch of lime juice; 8 oz. Coca-Cola. Serve over lots of ice in a highball glass.