Sure, though clearly I need to explain that it's not symmetric. I don't expect a filter to output a beautiful image. It is possible for some filters to be neutral while others spit out "ugly" results. And, of course, ugly is strictly my biased personal opinion, not an objective result.

What makes filters more ugly to me is filters that aren't very functional as a building block or a node in the middle of an image processing graph. When I said aesthetically unpleasant, I was thinking about design too, not just the aesthetics. Filters that include any aesthetics at all, frankly, are not very useful, and that is the main problem with many of G'MICs (and ImageMagick's) filters. Photoshop has some too.

I'm using https://gmicol.greyc.fr/ as the reference for filter names.

G'MIC Filters that are useful as a building block (filters you're likely to find used by professionals), and are not aesthetically unpleasant:

Basics, Colors|Channel Processing, Contours|Difference of Gaussians, Degradations|Blur, Details|Sharpen, Repair|Upscale

A small sampling of G'MIC Filters that are aesthetically unpleasant to me, primarily because they are poor building blocks (less likely to be used in professional work), secondarily because they add an aesthetic that I personally don't like, and try to do too much:

Arrays|Puzzle, Artistic|Ellipsionism, Deformations|Rain drops, Frames|Tunnel, Lights & Shadows|Shadow Patch, Patterns|Hearts, Rendering|Cupid, Sequences|Lava Lamp

Note that many of these could be re-created easily using proper image processing building blocks, like an over operator for compositing, or an expression node for image warping.