In the Philippines the best language is definitely English. I don’t think that any other language will do you much good. Older people may know some Spanish, and Tagalog has absorbed a lot of Spanish words from when it was a Spanish colony, but Spanish won’t help all that much.
English was generally useful to me in Indonesia, Malaysia, and Singapore. Because Indonesia and Malaysia are Muslim, you might be able to find a few people who know Arabic (as the language of the Koran), and Bahasa Indonesia has a lot of Arabic loan words. Singapore is majority Chinese so the most useful language besides English is probably Mandarin. The Chinese are also the largest ethnic group after Malays in Malaysia.
In Africa, as has been said the best other language is French.