Someone asked me over at ONTD why I wasn't a fan of Beren and Luthien, and I thought I'd save my response over here because, well, just typing it up made me annoyed, lol. I can't be the only one who thinks Beren/Luthien are the ultimate Gary Stu/Mary Sue combo, right?
Oh lawd, lol. First, Tolkien's stated that Beren and Luthien were meant to reflect the love between himself and his wife, so they're quite-literally self-inserts.
Now for Luthien: she's not just any princess, but THE MOST BEAUTIFUL PRINCESS EVER, SO SO SO BEAUTIFUL, MORE BEAUTIFUL THAN ANYONE THERE EVER WAS OR EVER WILL BE, and her hair is magic!!, and animals LOVE her, and she is THE BEST SINGER EVER and she is the only person who could sing Morgoth to sleep and the only person who could make Mandos have feels!! (but he can't actually change their fates so he convenes a special council of the Valar just to talk about her! because she is so important and beautiful and tragic!). And then she gets a Silmaril as a necklace and she is literally too beautiful for the world to handle because she and Beren die shortly after (but not before having a super beautiful baby).
And Beren: he's a super awesome warrior who fights ALL BY HIMSELF for years against HUNDREDS of Orcs in a dreadful place, and they come to fear him and he has the highest reward on his head (just as high as one of the Elven kings!! even though he's only, like, twenty). Then he bails and has ~many travels~ that no other man could bear, and finally he becomes the only person to break through Melian's girdle because he is just THAT special and THAT fated, and then Luthien herself the most beautiful woman ever falls in love with him even though he's probably fifty shades of nasty from wandering around in the forest all that time. But her daddy doesn't like him so he proves himself by doing the IMPOSSIBLE!! which no army of Elves or Men has achieved before!! and steals a Silmaril!! (oh, and along the way an Elven king dies for him because he is THAT important) and then he saves Luthien's daddy! And then he gets the girl.
So... yeah. I mean, at least Luthien is pretty badass, won't let Beren leave her behind, and actually does more to get the Silmaril than him, but they're basically the definition of Gary Stu/Mary Sue.
Also, on a somewhat related note, AO3 has pretty much ruined my life. So many fandoms, so many pairings... In the past month alone I've checked out the LOTR, Game of Thrones, Hawaii Five-0, and Alexander sections, lol. I should really start posting my own stuff there.