Britney was huge in South East Asia, almost MJ level.
I like to test how big an artist is by seeing if people above the age of 50 know about them
A lot of people above 50 don't speak English there but if they do, from what I've gathered, they have definitely have heard of Britney and MJ. Those from the younger generation have of course heard of a lot of artist, but I am considering people at my parents/grandparents generation.
From my experience, the only other artists/groups that older people MIGHT have heard of are Elvis Presly, Justin bieber, Backstreet boys, Celine dion (Titanic was massive), and now korean acts like Big Bang and BTS are everywhere. It has also got a lot to do with whether the artist's names are catchy to a non-native english speaker (For example, I'd say Beyonce is pretty hard to pronounce or remember for us)
This is just my experience, I could be totally off.