Personal reccomendations;
Philippines - Moalboal, fab diving, little else
Malapascua, good diving including very high chance of thresher sharks, small quiet island, some small, quite bars / resteraunts
Closest large population to these 2 is Cebu City, with some large hotel resorts, Shangri-La, Hyatt etc
Barrier Reef - Excellent Diving on outer reef, nice towns in Cairns and Port Douglass plus Rainforrest activities
Sipedan - World Class diving, rainforrest activities and culture activities a short and cheap flight away. Would have to split time, Diving / other
Bali - Fantastic diving in Komodo, best accessed by Liveaboard, so would require split time again, or there is some good day boat diving to go with the beach / rainforrest / culture activities on Bali. Be careful on Bali, some spots / towns have been "wiped out" by mass tourism, Kuta for example.
Palau - Excelent Diving, lots of big stuff and great shark, manta action, little else to do on the islands. Some WWII stuff on Pellilu Island
Thailand - I have only dove te Simmillans can be done either L/B or day boat, average diving, not real big stuff for most of the year but excellent access to nightlife and culture if diving day boat.