I haven't played one, but my son and his friends love the Eldritch Knight. And it feels like there is some literary support for the fighter with a few spells (although I can't think of one off the top of my head besides Mouser).
It feels like there could be a lot of flavor options to power the abilities - qi, bloodline, grit, panache, rage, psi, devotion, ancestral link, spirit guardian, ritual for the war God, the force, destiny's blessing... where most people have at least one that appeals to them as a splash of flavor on their fighter
All the people? I got nothing. Maybe for those wanting mundane a subclass that guarantees inheriting magic items if they don't find them?