There are probably as many ways to enjoy an evening out in Bangkok, as there are people there, although most people will head for the Patpong night-market area where many of the most vibrant nightclubs are situated. There is no avoiding the fact that Bangkok has a thriving sex trade, although it is clear which bars are part of this and which ones are not. There is a nudge-nudge wink-wink attitude that pervades Patpong and more people visit the area to enjoy the atmosphere than what is on offer.
There are also nightclubs in many of the hotels, and no shortage of excellent wine bars and pubs throughout the city.