Fallout: New Vegas

Fallout: New Vegas, developed by Obsidian Entertainment, is a post-apocalyptic action RPG set in the Mojave Wasteland. It is celebrated for its exceptional writing, deep role-playing systems, and the profound impact of player choice on the story and world factions. The game's reputation system, hardcore survival mode, and flexible quest design allow for a wide variety of character builds and playstyles. While built on Bethesda's engine, it focuses more on traditional RPG mechanics and narrative complexity than its predecessor.

It ranks highly for its masterful world-building, morally gray storytelling, and the freedom it offers in resolving conflicts. It's a paid title, with a dedicated modding community.