i've read a few really good ones, and a lot of either meh, ew, or why?
i think one of my favorites was a phanfic AU. it was where dnp were in opposing gangs, and phil ends up drugging dan and taking him back to his gang because they're under the impression that dan's gang is to one who took one of their members. so then they try to drug dan again so that phil can transfer him to people who can torture him for information. but dan managed to fool them into thinking he was out, and later ended up crashing the car with him and phil in it, and, long story short, they have to make the journey on foot through different gang territories and a post-nuclear war landscape with abandoned towns, cities, monuments, etc.. and they end up becoming good friends and (it's an ongoing fic) eventually they'll fall in love.
but yeah, no smut, some cursing, slow burn, no grammar or spelling mistakes that i've caught, character development, a+ plot, basically everything i love in a fanfic.
i, too, hate that fanfic gets a bad rep for smut, because that's just generalizing and stereotyping. a lot of it is entirely original, just with the names of real people or previously existing characters. and then people like us get labeled as weirdos or creeps for enjoying them sometimes.