I really enjoyed reading Deathlands by James Axler years ago. That name is actually a pseudonym and has been written by four different authors at various points. It's a bit disturbing at times, campy at others but overall entertaining. I love the idea of discovering hidden military bases scattered around the world after the apocalypse, filled to the brink with lost technology like time travel devices, implode grenades, etc. What's unique about this series too is that you can jump into it from any book. It gives a rough summary of the characters and what happened at the beginning of each title.