Places similar to Goa in South East Asia?

Hi all,

I've been visiting Goa for almost 2 decades and I love the place, minus the taxi mafias and overcrowded beaches mostly.

I am looking for places in South East Asia which have a similar vibe (the good things about Goa), are less crowded and not terribly expensive.

Any recommendations? I've been to Vietnam, doesn't really come as close. I love beaches, nature and tranquility and I like to stay away from crowds.