This review is long overdue as I dived in the Galapagos in July 2014. I have been lucky to have dived in many great places in the world at many sites that claim to be in the top10, but without doubt the best sites I have ever dived were at Darwin island and wolf island in the Galapagos. There were countless hammerheads and huge whale sharks not to mention all the other pelagic fish that inhabit the area (NB the currents are strong so it is not for novice divers).
These islands can only be reached as part of a dive liveabord boat and if you plan to book one then I highly recommend Leslie at:
http://www.divethegalapagos.com. Leslie booked my trip and then managed to do the impossible by getting me onto another dive boat (Galapagos sky), when my original booking (Aggressor) had to cancel 7 days before I arrived due to boat maintenance issues. Leslie managed the booking transfer as well as the refund from the Aggressor for associated expenses due to last minute flight changes (please note that although Aggressor canceled my original trip they were faultless in refunding the additional flight and accommodation costs that I incurred).
It is not cheap to do this trip but if like me it is high on your bucket list then you will find it is worth every cent.