Two series I deeply love:

Little Fuzzy
Fuzzy Sapiens
Fuzzies and Other People

H. Beam Piper - From 1962: What happens when human induced climate change causes a previously unknown race of people to mass migrate into human territory? On a world controlled by a corporation that only has rights so long as the planet has no native population?

Really light and breezy and the first one is public domain:

https://www.gutenberg.org/ebooks/18137

The Man Who Never Missed
Matadora
The Machiavelli Interface

Steve Perry - A soldier engaging in genocide on a backwater world has a religious experience and walks away. Through a few serendipitous events, he trains in a few unique martial arts and starts a one man campaign to bring the fascist campaign down. But not as himself, he's under no illusion that one man can survive. He builds a philosophy that attracts others to finish his work if he's unable.

Outside the core trilogy listed above, each of the major characters gets their own book:

Omega Cage
97th Step
The Albino Knife
Black Steel
Brother Death
The Musashi Flex
Churl