Pulau Sipadan- a diver's paradise! It's on the Eastcoast of Sabah/ Borneo. Fly from KL to Tawau or Sandakan. Share the taxi with someone to go to Semporna. Semporna itself isn't very interesting, no big nightlife. But check http://www.scuba-junkie.com If you like diving or you want to learn, Semporna's a great place for it. Also Malaysia is very cheap- so you don't need a lot of money to spend some days there, enjoying your daily dives, boat trips, good food and young coconuts.

Cheapest Way to dive Sipadan Mabul: Scuba Junkies. But it's a everydays ride all the way from Semporna with Speedboads. Scuba Junkies also got good accomodation and a bar.

Dragon Inn is a pleasant place to stay for a few nights, it is built on sticks over the water and reasonably priced.