Thailand does holiday accommodation exceptionally well for all budgets and has plenty of quieter spots, including places you might not expect from their party reputation (most beaches on Ko Phangan, for instance). That said, certain popular Thai destinations like Pattaya and Patong probably aren't most people's idea of paradise.
Vietnam is a fantastic and interesting country and Hoi An - the one readily accessible Vietnamese spot I'd consider paradise close to the beach - is genuinely beautiful, but not being sold a suit every five minutes is hard work!
Goa is interesting enough but tourist internet access is much worse than you'd expect in India outside cities. Mangalore isn't paradise, as pleasant as the city is.
Bali has a lot to recommend it but Kuta/Legian should be avoided and the internet on the Gili islands is rubbish. Langkawi is the one Malaysian beach destination with good internet. If you're looking for paradise beaches and internet then Cambodia is best avoided.
Kozhikode and Mangalore in India.
Also coastal cities in Goa, India as well.
Several cities in Sri Lanka might work too.
Also Playa Del Carmen + Cabo San Lucas in Mexico.