First I have to say that the Merlin fandom is the best fandom I've joined in a while. It's amazing, there's so little wank and it has some of the most creative and best fics I've seen so far!

I know some people on ファンポップ don't care for fic, but there's others that do like fic, and so I've compiled a 一覧 of fic I loved very much.
I have at least 44 fics saved in my memories on LiveJournal, so this is a VERY short part of it.
I'm not quite sure of Fanpop's policy on linking fic, so the highest rating I'm linking to is R, not NC-17. The ratings are always above the fic (except for one, I can't remember the rating either but it's so amazing that I'm linking it anyway).

I read mostly Arthur/Merlin, but there's some Gwen/Morgana and gen in here as well.

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One of the most well-known fics in the fandom, and a must-read. It's an AU where Arthur is a fratboy and teams up with Merlin in 書く class, to write a script for a movie, called MERLIN.

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Another really well-known one. AU, Merlin is a medical student and Arthur is the Prince of Wales.
(there is no rating on this fic, and I can't remember if it was really explicit, sorry!)

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Band!Au. Gwen/Morgana and Arthur/Merlin. They are all in a band called スラッシュ Dragon, and this is a fic that wonderfully uses all kinds of mixed media to tell the story.

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Gwen/Morgana. A story about how Gwen and Morgana grew up together, it's beautiful :)

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An absolutely hilarious story. Arthur/Merlin, Arthur and Merlin pretend to be each other in order for Arthur to escape a possible marriage.

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Another hilarious story, Arthur/Merlin, about a dragon that kidnaps Merlin. Arthur naturally follows but ends up liking the dragon.

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Beautiful. A story about how the characters we now know end up as the characters in the legend. It has wonderful descriptions of how Merlin feels the magic running through him, and if あなた don't like Merlin/Arthur, this is a great fic. It's not the point of the fic, it's blink-and-you'll-miss-it.

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A modern!AU in which magic does exist. Like with the 前 fic, Arthur/Merlin is there in this story but it's not a very important plotpoint. This is one of the best Merlin fics I've read, the universe and 書く is just amazing. It's pretty long, but it's absolutely worth it.

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A really short ficlet that it's too funny for words. If I give a summary, I'll give away the joke, so just read it.

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Arthur/Merlin. Arthur needs to marry in order to inherit a company, so he and Merlin pretend to be in love. Another modern!AU, and really funny. Poor Merlin.

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Arthur/Merlin.
I 愛 this fic. No fandom is complete without a Groundhog 日 fic.
I can't do a much better summary than the 作者 does:
'In which ドラゴン & ghosts & prejudices are confronted, Merlin wears a hat (twice) and a dress (once), Arthur breaks some crockery (lots), there are もっと見る pranks than pillowfights but at least one of each, and many secrets are revealed.'

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Another modern!AU wherein Uther is prime minister and Arthur is a politician. Merlin is his PA, and it's very funny.

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I cried, 読書 this fic. Merlin loses Arthur in time, but waits for him, searching every one of his reincarnations through the centuries. It's beautiful and bittersweet.

That's it for me! I have many more, but that would be a bit much. Share your recs in the comments, if あなた will!