The obvious choices are BKK KUL Or SIN.
My choice would be KUL. culturally diverse, not monotonous like SIN (heavily chinese with smatter of others). AIR ASIA which has a hub in BKK as well. Availability of accomodation and also Singapore is expensive by any standards.
Air asia routes taken by me include: Siem Reap for Angkor, Phnom Penh, Kuching, Brunei, Bangalore Madras and Cochin in India, also HK. Air Asia and its CEO Tony Fernandes has done more for the region than any single political leader! Great Malay Indian and Chinese food with a smattering of european ones to satisfy your craving if you desire so. McDo if your children are into it. easy wifi access. good transportation to other parts of Malaysia.
you can also easily get to Laos, all parts of Thailand, Indonesia and Vietnam.