The obvious one everyone mentions is 'World War Z', and for good reason. It's not just zombies, but the global scale of the collapse is so meticulously thought through that it makes the world feel terrifyingly real. Max Brooks uses oral histories from different survivors, which gives you a mosaic of the disaster's impact—military, political, ordinary people. It's less about a single group's survival drama like Rick's and more about the systemic breakdown and rebuilding, which scratches a different but equally satisfying itch.
If you want that ongoing, group-focused grind with different monsters, check out 'The Passage' trilogy. It starts with a government-made vampire plague and then jumps decades into the future. The middle book, 'The Twelve', is where the surviving communities and their conflicts really take center stage, very reminiscent of the Alexandria or Hilltop phases of 'The Walking Dead'. The tension isn't just from the 'virals' but from the other human settlements, some of which have developed creepy cult-like societies. It's a longer commitment but the character arcs across generations are worth it.
For something grittier and more focused on the immediate, brutal scramble after everything falls, I'd suggest 'The Dog Stars' by Peter Heller. It's a quieter, more literary take. A man flies a small plane around the Rockies after a flu wipes out most people. The prose is sparse and beautiful, and the loneliness is palpable. It doesn't have the large cast or the constant action of TWD, but it captures the psychological weight and the moral ambiguity of that world perfectly. Makes you think about what you'd actually do, not just what you'd hope to do. My copy's full of underlined passages about the silence of a dead world.
Also, don't sleep on 'Station Eleven'. It's a flu pandemic too, but it follows a traveling Shakespeare troupe decades later. The contrast between preserving art and just surviving creates this haunting, hopeful tone that's unique. It's less about the fight for resources and more about what's worth saving when the fighting's done.