Cafe del Mar
A franchise of the famous Ibiza club, offering a pool by the beach and chill-out music. The restaurant is pleasant but slightly overpriced and the outdoor seating is very nicely set up, although the volume is often cranked up way too high. Reserve in advance if you want one of the little pavilions.
Privé
Built on a private island connected to the mainland by a bridge, arriving here is half the fun. There's an expensive steak restaurant indoors and an equally expensive Japanese eatery upstairs, but the crowd-puller is the slick, breezy outdoor bar with DJ playing chillout tunes.
The beaches can offer some pretty wild parties on Friday and Saturday nights, especially if one of the on-again, off-again foam parties pops up. The New Year's Eve party in particular is legendary, as is ZoukOut (http://www.zoukout.com/), a massive yearly outdoor party organised by Zouk, featuring a roster of international and local DJs. Beaches, beer, bikinis and booming bass, what more do you need?
Bora Bora Beach Bar
Laid-back beach bar playing jazzy tunes.
There are a few nightspots of note on the mainland side of Sentosa Bridge.
St. James Power Station
Former power station now hosting no less than 9 clubs and bars with different themes, including Powerhouse for dance pop, Dragonfly for Mandarin/Cantonese live music, Movida for Latin rhythms and Bellini Room for jazz. Popular with Singaporeans and somewhat more downmarket than the options at Clarke Quay. Opening hours and prices vary per club, but most are open Wednesday to Sunday and charge $10-20 for entry including one drink.