Another nice place which is very near Singapore is Bintan, a 45 min ferry ride. There are many beautiful hotels/resorts depending on your budget. Ferry tickets are around S$45 for weekend (pls check the ticket fare). If you go to the World Trade Centre, you can actually get the tickets there. As for accommodation, you may check-out from Travel Agent, Straits Times, Classified section. Accommodation starts for as cheap as S$100 depending if there's a promotion for the period you are going.