I noticed that there is no section like this yet (or I haven’t found it). I think it’s helpful to make a list of the best free plugins around
Celestial by Acustica Audio should be an excellent plugin, I haven’t tried it yet but I have a lot of their stuff and I’m convinced that it cannot disappoint!
Unfortunately it is available for free until February!
I hope this thread is useful to you! add more plugins here!
Some free/intro/teaser plugins that may be worth a look:
Toolbox FRE is a handy starter kit for the kiloHearts modular ecosystem. It includes five snapins (EQ, chorus, delay, gain, limiter), which are also usable as ordinary plugins, and the snapheap host, for combining them in a modular fashion, with macro controls and modulation.
MeldaProduction offers free editions of 36 of their plugins. There are some restrictions in those (disabled GUI resizing, sonograms, preset save/load, oversampling), but they’re already quite capable and useful. https://www.meldaproduction.com/MFreeFXBundle