Recommendations for beach towns in SE asia

Hi all - i'll be travelling to Japan in december and wanted to take the opportunity to fly somewehere in SE asia and spend about 10 days there. What i'm looking for

1. As pretty a beach i can find. I'm picturing white sands, blue water, palms, basically a postcard beach (never been anywhere like this!). I do not mind tourists/people being there as long as it's not unliveable.
2. I'd like the beach/beaches to be near a town with a decently good night life. Not necessarily looking for party central, but definitely somewhere a bit lively. Extra points for places with a few beach bars

Philippines? thailand? cambodia? indonesia? - too many options so i'd appreciate first hand experiences.

Thanks!