Resident Evil... Early Resident Evil at least. Nothing beats the Raccoon City era of that series, nothing even comes close. So wildly iconic.

The Walking Dead. Love the comic book, enjoyed most of the show, and the games were also good even if Season 1 of Telltale's take on it was 10x better than any other season from them.

The Last of Us. I get why opinion has turned on TLOU over time from what I've seen, but that first game is just great. I like the TV show a lot.

World War Z Book: I don't read a lot but man I really loved that audiobook.

Dead Rising: I really love Dead Rising but it doesn't beat the other ones here for me as a whole, but that first game is perfect.

Project Zomboid: I believe this will be the ultimate zombie survival simulator...in about 10 years when it's all wrapped up, lol.