There are two major cities in Ecuador, each with a population hovering around 2 million: Quito and Guayaquil. While the places you see above will offer more natural beauty, Quito and Guayaquil offer breathtaking architecture, outstanding art and history museums, and all kinds of opportunities to take in Ecuadorian culture. Plan your trip based on your own tastes, but make sure you take the time to see both the rural and the urban areas, to make your time most enjoyable.
Sources
http://en.wikipedia.org
http://countrystudies.us/ecuador/20.htm
http://www.anytravels.com/south_america/ecuador/