I must say Bangkok. I think the Philippine people are friendlier and easier to communicate with, but Manila is such a mess of a city compared with Bangkok. Both have terrible traffic, but atleast the Bangkok skytrain can get you to major destinations. The hotels were cheaper in Bangkok and the level of service much better and more efficient. Also Bangkok is a much safer city. There are parts of Manila that I would not advise a foreigner to venture into. Bangkok also has more variety of food and great tailor shops. Both are terribly hot in summer time.
My advise would be if you know someone in the Philippines then you'll have a great time. If you are a solo traveler Bangkok will be better.