Havana - the Museum of the Revolution, the market in the week and the atmosphere. All the old 50s cars and the back street music cafes.
Trinidad - Plaza de la Musica - excellent outdoor music venue with dance floor and fabulous musicians.
Be firm with people hassling you, and they will usually give up after one time of saying 'No'.
Best Way To Get Around:
On a tour or hire a car. Trains are scarce, and it can take up to 3 months to get a ticket. Planes are not recommended, as they are not very safe.