The List So Far
Barbarian: Path of Instinct - An instinctual warrior who's rage is a state of perfect focus.
Druid: Circle of Elements - A druid that manifests elemental powers to manipulate the battlefield.
Druid: Circle of Growth - A plant druid who conjures a seedling that's empowered as they use their magic.
Fighter: Adventurer - An resource fighter that always seems to have a spare potion or scroll. The most basic form of adventurer.
Fighter: Brawler - A rough and tumble fighter for whom anything (or anyone) nearby is a weapon.
Ranger: Bounty Hunter - An urban ranger who tracks down their pray... dead, alive, or some mix between the two.
Rogue: Divine Hand - A holy inquisitor who's original subclass name was stolen by a non-holy inquisitive rogue.
Sorcerer: The Fiend - A sorcerer that inherited a darker legacy... blame Warlocks (...or Bards).
Sorcerer: Sea Soul - A waveborn sorcerer that push about their foes with the turbulent power of the ocean. Originally inspired by a UA concept, but long sense set adrift.
Warlock: The Dragon - The lowest hanging fruit. The pages that were clearly just missing from Fizban's. The most obvious answer to the question "why does that not exist?"
Revised Subclasses
Champion Fighter - The classic stalwart Fighter, now with just a bit more going for it.
Assassin Rogue - The classic sneaking and stabbing Rogue, now with a bit more sneaking and stabbing.
This isn't super clean, but just serves as all the GMBinder versions stitched together as I know that some people prefer PDFs or have issues with GMBinder not working.
Foundry Module Manifest URL
https://raw.githubusercontent.com/KibblesTasty/kibbles-generic-subclasses/main/module.json
The Wide Net of Ideas
I've pooled all the ideas so far, runner ups, new ideas, etc. I've culled a few that I either tried and failed to make work, or that have since appeared in another form (for example, Hedge Mage got poached by the Occultist).
I've also posted this list over on Reddit with a call for any new ideas... but worry not, sole voting power remains in your hands.
https://www.reddit.com/r/dndnext/comments/v2gl3q/that_monthly_what_subclasses_can_you_not_believe/?
All the best,
-Kibbles