You want to really understand the whole zombie apocalypse and what makes it so interesting, you gotta go back to it's creator. And no, not George Romero, he has been the one to make the biggest contributions to the genre, but he wasn't the creator. The real creator was Richard Matheson, and in his novel, "I am Legend" it didn't even have zombies, but an army of vampires. It's the whole, you vs the world, idea, that in the end we're all alone in a world out to get us. So you can really use any monster to fill the billet, the reason's why zombies work so well is because they reminds us of ourselves. It wouldn't be the same if it's one man vs. an army of creatures from the Blue Lagoon. A bunch of fish people. Zombies reminds us of ourselves, and they remind us that no is to be trusted, and we're all just apart of some sick rat race where the ultimate goal is be the only ones to make it to the finish lines, succeed when everyone else has failed. There's a sense of tragedy in it all, seeing how only a few can survive while everyone else has to perish too.
Funny thing about the Richard Matheson's I am Legend, it went a step ahead of most of today's movies, even though the book was written in the 50s. In the book you eventually discover that the biggest monster in the story aren't even the hoard of zom... I mean vampires out to get the main character. That book is still ahead of it's time, and the Will Smith movie did it no justice.
Anyways... personally I get bored of zombie shit. I rather stick to something that is VERY plausible when it comes to post apocalyptic material. Mad Max, nuclear holocaust, Fallout is where it's at! Beyond thunderdome is where humanity is really headed since there's nothing fictional about nuclear Armageddon. So yeah!
lol