Alright, so I'm definitely one of those people who goes back to Merlin fic when I want that specific blend of medieval fantasy and found family dynamics, but with magic cranked up to eleven. The canon show always felt like it held back, you know? The best adventure fics for me are the ones that run wild with the 'what if'—what if Merlin's magic was discovered earlier, what if the purge never happened, what if Albion united against a bigger threat than Morgana? They take the world's bones and build something epic on top.
I keep coming back to 'The Once and Future Queen' by Astolat. It's technically Arthur/Morgana, which I know is a divisive ship, but the world-building is insane. It's less about romance and more about a magical political thriller with Arthur and Morgana as reluctant allies against Uther. The magical systems are detailed, the quests feel high-stakes, and the adventures span kingdoms. Another one is 'The Crown of Elfland'—a crossover-ish treat with Fae lore that sends Merlin and Arthur on a perilous journey beyond Camelot's borders. It nails that classic heroic quest feeling but with way more magical creatures and ancient pacts than the show ever dared.
Honestly, my favorite thing about these kinds of stories is they treat magic not as a secret to hide, but as a force to explore, tame, or fight against. They give you the grand adventure the show promised but often delivered in small doses.