Most countries I've been to use Visa as their most common card. Living in a major Asian country and every bank and credit card company offers Visa as their main card as well.

China is kind of an outlier with Union Pay, and while a large number of countries offer their own alternatives, I'd say most are Visa-first. Apparently about 37% of cards around the world are Visa, so that's a huge chunk. JCB is the biggest non-Chinese non-American provider by revenue, and even they're a minor player in their home country.