A-OK

I once read that the term "okay" is the most recognized word in the world, and in Thailand, taxi drivers use it a lot. Cabbies here also love to express their approval of something by saying that its "number 1". For example, when I speak Thai to the drivers, they often say, "you speak Thai #1".  And then, of course, there's always the thumbs up signal which, in my opinion, is the ultimate universal gesture of endorsement.