u/reviedox

Global Defense Initiative - a peacekeeping force from Red Alert, has some nice unit designs

XCOM - the basic XCOM soldiers look fine, but the new resistance factions look even cooler

New California Republic - I'm not the most experienced with Fallout lore, and many will probably tell me that they're closer to morally grey, than being the good guys, but despite its flaws, they are one of the better factions in the post-apocalyptic world, and look very cool

Iron Front - that's not a Nazi march, that's Iron Front, an organization formed during Weimar Republic's turmoil, dedicated to fighting anti-democratic elements, such as fascism, communism and monarchism

The last image is the reason I made this list, which I kind of struggled with, as I'm not aware of many good guys factions that simultaneously look cool, and had to improvise a bit, so would like if some could share their favorite designs