Check out these videos on retiring in Southeast Asia. Malaysia looks like the winner but some of the other locations like Cambodia, Thailand and Vietnam also have their advantages depending on your personal circumstance.
I have to agree with Ryan from Snail Travelers on his accurate description on life in Malaysia. One thing to consider for any prospective retiree is the level of English proficiency in the host country. Malaysia stands out among the countries covered in the videos below. However, I have noticed that many Cambodians, Vietnamese and Thais now speak English as a second language.