RULES:

•Only one entry per franchise.

•Has to stay indie/didn't turn into a behemoth: no Minecraft, Rocket League, Fall Guys, etc.

•I decided to include indie-developed, when a studio was hired by a major publisher.
HOWEVER, I'm only including games made SPECIFICALLY for a new franchise, i.e.
The Stretchers was developed by an indie studio, and published by Nintendo. It's a new franchise. That's OK.
Metroid Dread was developed by an indie studio, and published by Nintendo. It's also Metroid. That's a NO.
I wouldn't nominate those in the latter example for "Best Indie Game" in a serious awards ceremony, though. No one would, right?
I decided in favor of this for my list, as in recent times we've had our Devolver Digitals, Annapurnas, Humbles and such.
Big dogs funding indies, such as Microsoft lending a hand for Tunic and Cuphead and so on. Others like Island Saver, which was published by A BANK?!
All of this, in my opinion, kind of expands the definition of an "indie game". Many of the most popular ones aren't truly indie anymore. However, they still play and feel like one.