George A Romero is definitely worth checking out. He’s earned the moniker “Father of the Zombie Film,” and for good reason.
If you’re into classic movies, I’d suggest starting with Night of the Living Dead (1968). That one really turned heads when it came out. If classic movies aren’t really your thing, Land of the Dead (2005) is a very fun romp.
Day of the Dead (1985) is probably my all-time favourite movie. I appreciate that his movies are not only fun zombie movies, but they also have a message behind them. Day of the Dead is full of existential dread, and touches at the meaning or absurdity of life, and how that means different things to different people.
In each of his zombie movies, although the undead do pose a mortal and existential threat, Romero holds up a mirror to humanity and says that its our innate inability to cooperate which dooms us. It’s a powerful message, and one that seems to have held up for the past sixty years if you follow the news.