One of the best places in the world to enjoy marine creatures, Pulau Sipadan has long been and for a long time will be a diver's paradise. Located off of the east coast of Sabah, this protected area actually has no accommodations and is somewhat hard to get to; you'd have the hour boat ride from Semporna, which may only be reached in the first place by a lengthy taxi ride from either Tawau or the much more distant Kota Kinabalu. But if you love the water, you can't let that deter you.
For divers and snorkelers, you must see for yourself the incredible beach dive where the main resort used to be; after wading about thirty steps into the gorgeous water, the reef wall drops nearly 3,000 feet! There are plenty of coral, macro-fish, sharks, turtles, and so much more on every dive, which is saying a lot when many top sites around the world can be hit-or-miss. For more information on dive centers that service the area, consult the included link.
Note:Sipadan is not the only island in the area with access to stellar dive sites. Try Lankayan and Kapalai, both of which have top-notch accommodations and cater to divers. The Sipadan-Kapalai Dive Resort is an incredible modern resort built on stilts in the water that must be seen to be believed.