1989 or Taylor never felt big so obviously Adele.

25 is technically bigger, but Taylor was bigger during 1989 than Adele was during 25 as a celebrity.

Maybe 1989 just because it had more singles (which were properly released & promoted) but other than that, 25.

I'm also not from the US and I agree 1989 doesn't feel as big as some of ya'll say it was. It was local for the most part.

21 is by far the biggest era of the decade. Then 25.