Duffy and Shellie May pins
Not *AS* popular as they are in Japan and Hong Kong. Disney didn't really give Duffy enough time over here to gain momentum (and actually kind of mis-handled that group of characters in general). We had a small wave of pins and such when he first got re-released over here in 2010 until about 2015, then they stopped making them pretty much completely (except for Aulani). That said, there's definitely a following. Besides myself, there are several Duffy, Shellie May, and Gelatoni fans on this forum alone.
If you ever get a chance to go to Tokyo DisneySEA, definitely do so! It's amazing, how they do Duffy et al over there, and it's the best Disney park in the world, even setting Duffy aside!