Recommended Media
Note: Any links were attached for your convenience. If they don't work or aren't to your liking, find the media yourself.
Manga
Anime
Features a tsundere, mystery-solving loli in a fictional European country in post-WW1 Europe. Towards the middle it has some episodes that feel a bit like filler, but it's worth a watch by the end of it. 10/10.
A hidden gem that unfortunately will likely never ever get a second season, Dantalian is often what people who had issues with GOSICK seem to like instead. It's one of the only animes I've ever heard of that has Bergmann pistols in it and best girl has met Hitler canonically. If you can find it somewhere (a daunting challenge in and of itself!), give it a shot.
A testament to the strength and resolve of all mankind. I would not miss out on it for the world.
A manga and show that the illustrator of GOSICK created before her unfortunate passing. It follows a Japanese girl who has moved to Paris in the late 1880's, covering quite a rare setting in the process. You can also watch a cute girl eat French bread a lot.
Music
Film
Technically a television mini-series, anything adapted faithfully from the works of Jules Verne is going to be a masterpiece.
My favorite film. An infinitely rewatchable take on the board game you've played before at least once. It's on Youtube for free.
A promotional film recorded in 1939 for the World Fair, this short film is a rare genuine glimpse into life back then. The film showcases the developing technologies that will dominate the next century, the hopes of the American people for the future, espouses the values of the general American populace (which many in today's media wish to hide from you!), and features footage of a time capsule buried and not to be reopened until the year 6939. The film is a genuine gift from the people of the past to us.
Study Material
Learn to speak like an adult ought to.
Read a magazine from over one-hundred years ago.
An avid collector of talking-machines' information dump.