El Floridita is one of Havana's most famous bars and restaurants — a historic Art Deco establishment at the western end of Calle Obispo that claims to be the birthplace of the daiquiri and was the preferred daytime drinking establishment of Ernest Hemingway for the years he lived in Cuba. It is, therefore, extremely touristy and extremely expensive by Cuban standards.
Whether it is worth visiting depends on your relationship with Hemingway mythology. The bar itself is beautiful — red velvet, mahogany, a long counter with bar stools, and a bronze Hemingway statue at his habitual end. The daiquiris are genuinely excellent and mixed in a style unchanged from the 1950s. The restaurant serves decent Creole seafood. Go in the early morning before the tour groups arrive; the daiquiri before noon is very cold, very well made, and surprisingly reasonable when you do not have to queue for it.