I came up with this because I learned from Tumblr that there’s apparently more than a hundred fanfics for The Epic of Gilgamesh on Ao3, and I think it’s poetic in a way how we’ve still never really gotten over the first story ever.
My answer would be Le Roman de Silence, from the early 1200s, which is about the adventures Silence, a boy who was born as a girl (that’s the author’s way of describing him)and who eventually becomes a knight. I just stumbled across it randomly but I fell in love with it after reading it the first time, and I think it’s beautiful how something 1000 years old can still be around and not have lost any of it’s capability for arousing our emotions.
For me it’s Sir Walter Scott’s The Lady of the Lake. Published in 1810; it’s a fun story, but more than that - his command of the language was breathtaking. When he describes the water flowing over rocks in a brook, you hear it.
Also notable for two (of several) songs that he wrote in this, that his characters sing. One is “the boat song” that the clansmen sing while rowing, about how great the Chief of their clan (Clan Alpine) is, which starts “Hail to the Chief who in triumph advances…” This became Hail to the Chief, which is played when the US President walks into a room. The other is a hymn that Ellen (the eponymous lady of the lake) sings as a prayer to the virgin mother, Mary - an ave to Maria. A few years after it was published, the book crossed the English Channel and this guy Schubert read it - and thought, hey, I could put that to music.
On top of all that, it’s got a twist ending that 200+ years later I DID NOT SEE COMING. Bastard had me hook, line, and sinker. Brilliant.
Anyway, it’s my favorite.