I love 3D World. I’m not sure if any game in the Mario series can be called “underrated,” but if there is one, it’s definitely that one for me.
The music is fantastic, there’s a fun variety of gameplay ideas that usually get pushed a little further each time they pop up but never feel overused, and getting to use classic-style power-ups with different characters was the kind of stuff I dreamed of when I was a kid.
(I’m actually playing through Bowser’s Fury right now, and having a lot of fun with that as well. Glad I decided to double dip on Switch!)