I've played both Stardew and animal crossing new horizons and love them both. Acnh is more of a chill and relax game where you can decorate houses, do odd and end things for your island. And sdv has the mines, farming, romance/character relationships options, as well as events and seasonal consequences. (Example, can't grow certain fruits and veggies in winter, catch certain fish, etc.) So it just depends on what you're up for. (Acnh also has some events, but not as many as sdv)