Fallout: New Vegas is essentially a big choose-your-own-adventure platform with several major choices of varying mutual exclusivity. The real heart and soul of FNV, though, is in the incidental stories found in side quests and companion quests--while they are rarely necessary to "win the game" (i.e., trigger the credits screen), they are often more compelling than the major quests (find the MacGuffin and pick A, B, C, or D) and allow much greater opportunity for forming the player character. I'm not sure that you'll find the total storytelling better than that of a good or great book, but I think New Vegas still leverages the type of narration that is unique (but not guaranteed) by video games.

edit: Just remembered that Planescape Torment was created by Black Isle, the studio that also worked on the first two Fallout games. Black Isle later dissolved, but the key players later formed Obsidian, the studio that developed New Vegas on Bethesda's behalf. I imagine it's very likely you've already played FNV (in which case, I'd love to hear how your experience aligns with mine), but if not, it's probably up your alley.