my favourite drink is a mojito! I never make them because don't ever have fresh mint, and living in Toronto, it's hard to find a restaurant that makes them.
hope to have lots and lots when I go to Miami next week!
I lived in Miami for 3 years! You'll be hard pressed to find a mojito under $15 on South Beach, so I don't know if any of them are good (strike that- I have been to Yuca on Lincoln Road and they do make a very good mojito).
But I would highly recommend if you have a rental car to head off the Beach to Calle Ocho to go to Versaille - it's the most famous (touristy but good) Cuban restaurant in Miami. They stick a real sugar cane stick in the mojito, they're not overpriced, and they are delish!!!
Also, my all-time favorite restaurant is Ceviche 105, located in downtown Miami (not Miami Beach), and they make Pisco Sour, which is a Peruvian drink that is amaaaazing. If you like raw fish, hit up their Ceviche Mixto - mmmmm!