Resident Evil: 10 Reasons It's The Best Horror Franchise Of All Time
1. Complete Package
In 2012, a game called Gotham City Imposters launched on home consoles. It wasn't a particularly good game, but it stuck with this writer for one very specific reason; the game launched with well over 100 different paid downloadable content items.
Now, granted, the majority of Resident Evil games released either before downloadable content was a thing, or on platforms that are incapable of adding new content.
Of the games released that can have DLC, all but one (Revelations 2) had less than 10 paid items available through its lifespan, if you don't count compilations of DLC or episodes in the episodic games. And three of those added in extra modes and side stories for free.
Capcom is a company known for rereleasing games with minor changes and experimenting with DLC monetization, but this doesn't seem to apply to Resident Evil.
With those games you normally know what you're getting up front; an insane story about those in power experimenting on those without and making monsters of them, challenges in the story mode to unlock new things, and usually at least one free mode of play on top of that story.