I vote for GoW, but if you are looking to snowball it, play TF2 first since the campaign is short but awesome! Then GoW. It’s decently long, but mostly linear. Then after that, probably Bioshock for similar reasons. Finish it off with Horizon, which can be as wide open as you want it to be, but you can also mainline the main quests to get a more streamlined story experience.

Also, I’m the lead mod over on !playstation@lemmy.world so come join us over there if you haven’t already!