I went to Cuba last year and I loved the experience. It's completely different from the other countries I've been to, with the mixture of the history, the revolution, the political system, the culture, the people...
It has beautiful spots, such as beaches and historical buildings, and extremely friendly people.
There are lots of nice citys to go there, but the ones I liked most were La Habana, Trinidad, Remédios, Viñales y Cayo Las Brujas.