三人行，必有我师(焉)

I was just looking at DVD listings a few minutes ago and was reminded of 国语 as another option (though this apparently refers to any national language, e.g. it means Korean if you're talking about Korea, and apparently in Taiwan it specifically means Taiwanese Mandarin as contrasted with 普通話...). Wiktionary also suggests 中国话, which seems pretty neutral and clear to me, as referring specifically to the "national language of China," but I don't know if that one is in common usage. I've heard all the others, but can't remember hearing 中国话...