Galapagos Master
I've been on the Galapagos Master twice so far, and I fully enjoyed both trips.
I chose the 10 night trips over the 7 night trips to get the extra days at the better dive sites. The highlights were iguanas, mola mola, and hammerheads.
Cabins were confortable and better than most other liveaboards, and the AC worked well. Food was pretty good and served buffer style. Staff is friendly and goes out of their way to know the names of the guests. The dive operation was run very well with an emphasis on safety, which is important when you are out at remote islands.
"Big JC" was our favorite dive guide, he always had a lot of enthusiasm and knowledge about the dive sites.
The trips are expensive, but not more so than the other Galapagos liveaboard options. This trip hits the highlights of diving the Galapagos and I can highly recommend it.