A buddy of mine kept going on about this one story where Aerith survives the Temple of the Ancients. Not a single person believed him that it could work without breaking the world, but the author pulled it off by treating the Planet's will like a river you could divert, not a dam you could break. Cloud and Aerith end up as these weird, tragic drifters trying to undo a fate they've already sidestepped, and the relationship is this brittle, guilt-ridden thing because he still has all his memories of the 'real' timeline. It's heavy on the existential dread and not much fluff, which honestly fits the source material better than most fluffy AUs. I burned through it in two nights, and the ending left me staring at my ceiling for a solid hour—not because it was sad, but because it was so strangely peaceful, like watching a ghost finally decide to move on.
My personal bias is toward stories that explore the Lifestream connection. There's a fic that treats the Lifestream as this vast, noisy library of souls where Aerith is kinda... stuck, but aware. Cloud's consciousness keeps brushing against hers whenever he sleeps or gets seriously injured, and their conversations are these fragmented, dream-logic things. It's less a romance and more two people trying to rebuild a bridge between life and death using only echoes. The author's prose gets incredibly abstract, sometimes frustratingly so, but when it clicks, it feels like you're reading something whispered. I'd take that over five coffee shop AUs any day, even if I need a flowchart to keep up with the metaphysics.
Honestly, a lot of the 'best' storylines aren't the epic novel-length ones, but the smaller character vignettes. One that stuck with me was just Cloud helping Aerith rebuild her church flower bed after a plate collapse, brick by brick, in total silence. No grand confessions, no destiny talk, just two people who are really bad at talking finding something quiet to do with their hands. That sort of understated, wounded healing hits way harder for me than another retelling of the golden saucer date.