In November 2011 I went on the Tropical Birding Galapagos Endemics cruise. This was an eight day cruise around the famous Galapagos Islands group which are in the Pacific Ocean about 1000 km west of Ecuador. The islands are famous for the part that they played in Charles Darwin's development of the theory of evolution and natural selection. The cruise was simply amazing, not just for birds but for the whole natural world experience of birds, land animals, snorkeling with the fish and penguins, whales and the stunning scenery. Truly a trip of a lifetime and highly recommended.
See http://www.tropicalbirding.com for the trip report and for the schedule of this and their other tours.