Here's one that I found rather well written but it's not done yet tho... Yet it's plot so far is rather captivating so I'll recommend it:)

Solace and a Smokescreen
It's like Avengers Tower gets turned into a battlefield when Loki and Bucky meet. More often then not they are at each other's throats. However, do these two former villains really hate each other as much as they want the world to believe.
https://www.fanfiction.net/s/10440720/1/Solace-and-a-Smokescreen