Day 27: A game or series with really impressive or in-depth lore
I'm not even the biggest Elder Scrolls fan, but even I can admit they really put effort into their world-building and lore. Dark Souls is another one with great lore, but I've yet to play any of those.
For a JRPG, Suikoden does a pretty good job as well. With each title (maybe aside from the fourth) they slowly expanded on the game's world, history, and recurring characters. Too bad Konami has officially killed off the franchise!