It’s only a duology and not sure the author had any intentions of doing more but Rise Again and its sequel Rise Again: Below Zero are great. Ben Tripp is an accomplished political writer and has a way of humanizing his characters, especially the lead character, that I found refreshing.
I also really enjoyed the first novelization of The Walking Dead by Jay Bonansinga, The Walking Dead: Rise of the Governor but later books suffer from...something. Probably being in the TWD universe?
If you’re into short stories I thought Nights of the Living Dead was an excellent collection. It’s got gore, goof, and gravitas, something for everyone.
I still need to finish Sophie Littlefield’s Aftertime trilogy, but that’s a strong series.
I recommend Ben Tripp’s [Rise Again](Rise Again: A Zombie Thriller https://www.amazon.com/dp/B003UYUS6E/ref=cm_sw_r_cp_api_i_gLybDb2K49HPJ). It’s incredibly well-written. I enjoyed the sequel but it strayed close enough to jumping the shark it took a little effort to get through.
I also really liked Sophie Littlefield’s Aftertime and it’s sequel, but I haven’t read the third.