Stroke off one filter, because in Gimp 2.10 the JPEG export has a "how preview in image window" options that shows you how bad the image becomes and how big the file is in real time, and therefore replaces most of the "Save for web" plugin.

Otherwise there are few of my filters that I use very regularly: preset-guides, path-to-shape, path-edit, layer-tiles, perspective-stack, imgur-upload off the top of my head.

What I use the most depends on what type of project I'm working on. Right not I'm doing family photo restoration, color and lightness/darkness adjustments, some scratch and defect removal, depends on the photo for what plugin works better, i'm learning much, and sometime forgetting just as quickly. curves, gmic, several others.. need more time in the day to play with them.

Plugin would be GMIC, still finding new things in there
I use the enhancement tools alot
The colour menu tools
Filters - I use Nik's define 2 rather than any gimp denoising or GMIC ones.
I rarely use any scripts and other plugins now

Because in all my old works and particularly glass works from 2014 onward, I used Bevel Reflect Logo from Gnu Tux, it was and still is my favourite and the one I use most. Nowadays I use it to work wonders with mandalas..

Next comes Ofnuts 'Generate Intermediate Paths', then 'Lines Between paths' from Trandoductin.

As requested here is a copy of Tim's Lines Between Paths plug-in.

My favourite filter for denoising and smoothing before I found Niks denoise was 'thin brush' but it often smooths the photos in a way that distorts them. Many of the denoise and smooth filters are made for large photos, not smaller ones