It's top 3 with Born This Way and Beyonce.
Top 5 with 21 and Born To Die.
So yeah it comes down to personal taste whether you'd put it at number 1 or not.
My personal best of the decade is Born This Way
Teenage Dream is far weaker and less inspired version of 1989, so how can people mention it ? As solid of a POP album as it is, Clean alone ***** all over it. When you add Blank Space, Wildest Dreams, Style, Out of the woods, Stay, Wonderland etc. >>>>>>>>