This, You Protect is one of my favorite fics ever! I was going to recommend it as well. Also:

Gen:
Brothers In Arms by copperbadge
Bucky gets a new pet.

Bucky and Mr Rogers by impertinence
"Bucky accidentally becomes a surrogate brother to half the neighborhood, purely via the power of PBS."

Clint Barton’s Home for Wayward Mind Wiped Assassins by roguewrld
Clint owns a small, run-down apartment building. Bucky shows up and sort of starts living in it.

Sunshine and a Flock of Steves by Bluandorange, zetsubonna
In the process of destroying Hydra facilities, Bucky discovers something unexpected.

Steve/Bucky
Steve Rogers at 100: Celebrating Captain America on Film by eleveninches, Febricant, hellotailor, M_Leigh, neenya, tigrrmilk
A fantastic metafic about all the movies Steve didn't know had been made about him.

I love you like rlb by tolieawake
Fluff.

like setting off fire crackers at midnight by what_alchemy
"Everyone who knows the Captain America story thinks they know the Bucky Barnes story. In the 21st century, Steve is still keeping Bucky's secrets."