Rum, Coca-Cola, and fresh lime — not just a rum and Coke. The lime makes all the difference.
The Cuba Libre was allegedly born around 1900 when American soldiers in Cuba mixed Bacardi rum with the newly available Coca-Cola and toasted with 'Por Cuba Libre!' ('For a free Cuba!'). The Coca-Cola Company spread the drink internationally through a 1940s advertising campaign.
The critical distinction between a Cuba Libre and a Rum and Coke is the lime juice. The citric acid from fresh lime brightens the drink, cuts the sweetness of the cola, and adds a complexity that the two-ingredient version simply doesn't have. Use a white or light rum — gold or dark rum can work but changes the character significantly.
Use dark rum (Gosling's Black Seal) and ginger beer instead of cola. Crosses into Dark & Stormy territory but with a lime squeeze.
Use an aged añejo rum instead of light rum. More complex and less sweet — the cola flavours marry beautifully with oak-aged spirit.
Add 2 dashes of Angostura bitters and a dash of falernum to the standard recipe. The warm spices complement the cola and lime in unexpected ways.