fern. is accepted!
Fanfic recommendations...
Ronald Weasley and the Very Friendly HorcruxK+, humour/friendship, ongoing, crossover with Harry PotterMost crossover fanfics completely ignore the fact that characters are entering a world with very different logistics to theirs. This fanfic, however, goes into depth with how the character in an unfamiliar world (in this case, Al in 1997 England) would actually work, rather than it just magically being glossed over in two sentences.
(Tangent: I once read a HP/MLP crossover where they let a random unicorn they just met attend school... seriously?) Also, unlike most HP/FMA crossovers, this isn't the cliché "same plot but with Ed in it"; Ed doesn't even appear until chapter twelve in this fic. While the actual writing may not be the best (Ron, why would you tell a random Muggle you just met all of that stuff?), they've got the concept down perfectly. And the humour is good, too.
What Lies Behind UsT, family/adventure, ongoingIt's a continuity fusion, and also shows us what Ashphonse was up to during the interm after Laws and Promises (FMA03 episode 51). Is that all I have to say? There are barely any fanfics based on either concept. Also, Little Wrath is great in this fic. They do gloss over the fact that there are two Eds coexisting, mind. =/