From MIA, here is where you get to non-stop:

American Eagle:
Ft. Myers, Key West, Jacksonville, Marsh Harbour, George Town, Nassau, Freeport, Pittsburgh, Cincinnati, Charlotte (eff. 6 January), Columbus, Richmond (eff. 6 January)

American Airlines (domestic):
Atlanta, Nashville, New Orleans, Tampa, Orlando, Raleigh, Charlotte, Washington Dulles, Washington National, Baltimore, Philadelphia, Pittsburgh, Newark, New York City JFK, New York City LaGuardia, Boston, Hartford, Cleveland, Indianapolis, Detroit, Chicago O'Hare, Minneapolis, St. Louis, Houston, Dallas, Las Vegas, Los Angeles, San Francisco, Denver, Vail/Eagle, San Juan, St. Croix, St. Thomas

American Airlines (int'l):
Grand Cayman, Orjanestad (Aruba), Port of Spain, Bridgetown (Barbados), St. Maarten, Providenciales (Turks & Caicos), Kingston, Montego Bay, Santo Domingo, Santiago, La Romana/Casa de Campo, Puerto Plata, Punta Cana, Port-Au-Prince, Mexico City, Cancun, Guanacaste Liberia (eff. 31 January), San Jose, Belize City, Panama City, Managua, Tegucigalpa, San Pedro Sula, San Salvador, Guatemala City, Caracas, Maracaibo, Cali, Bogota, Medellin, Quito, Guayquil, La Paz, Santa Cruz, Lima, Santiago de Chile, Buenos Aires, Sao Paulo, Rio de Janeiro, Montevideo (via Buenos Aires), Asuncion (via Sao Paulo), Madrid, London Heathrow, Paris

Codeshare services:
Zurich (Swiss), Helsinki (Finnair), Santiago de Chile (LanChile), Madrid (Iberia), Sao Paulo (TAM)