Mine are the Hisuian balls, specifically the Hisuian ultra ball. I just love the design of the latch, and the color palette used for all the balls. I especially enjoy the little flourish on the yellow stripes of the ultra ball!
What's your favorite? Any particular reasons why?
Give how niche / useless some of the balls are color matching is really the one joy you can have with them. Doubly so when you are dealing with apriballs where you often only have a limited amount