Folders in the Graphic Styles palette.
I draw comics, and use Graphic Styles to keep my characters consistent across panels and pages.
A simple character might involve a half dozen styles. A complicated character can involve a lot more - see the attached screenshot.
Add in a good chunk of Graphic Styles for recurring background elements and I'm constantly dealing with triple-digit number of entries in the Graphic Styles palette. Finding the set of styles I want to use becomes an increasingly tedious process as pages get more complicated.
I would like to be able to create folders of Graphic Styles, which I can open and close in a similar fashion to opening and closing layers.
Being able to nest them would be nice; in the attached screenshot I have styles for two variants of a character's vehicle, with their own subsets of styles for drawing them at different sizes. Being able to nest all of these into "KIRT MECH" would be great for when I'm working on a page involving three giant robots fighting.
I would also really really love it if these folders were preserved when pulling styles out of a style library, or when copying art to another file.
Basically I have been using a LOT OF Graphic Styles to make some pretty complicated artwork, and I am finding myself direly in need of a way to fold away the parts of the complexity I'm not thinking about at the moment.