Winter Soldier + Black Widow Movie

Open in Russia, Bucky on a job.  He completes it because he's a badass and goes back to whatever safehouse hole-in-the-wall he's staying in.  Eventually, he sleeps.  But it's troubled sleep because he's a troubled dude.

Cut to the train scene from Captain America.  Bucky falls, but is still alive.  He's found by Russian HYDRA, because HYDRA's freaking everywhere in this universe.  Cut that scene short, because we can't give away too much too early, and Bucky awakens to find Black Widow in his safe house.  He's got a gun on her, and she asks, "You don't remember me?"  He says, "I don't remember much."  She starts to tell him about their past.  He doesn't believe her, except that he really does, but love or some shit.

They go around shooting a bunch of people in the head while we're shown flashbacks of their past adventures over the decades.  He was trained, brainwashed, given a Cable-arm, and frozen whenever he wasn't on a mission.  She was trained, given a knock-off super solider serum that enhanced her (but not as much as Cap) and slowed her aging considerably.  Bucky wasn't given the same serum because reasons.

As Widow and Bucky go about dismantling the Russian equivalent of Weapon X, they're stopped by Yelena Belova (as the new Black Widow), Crossbones, and their boss Baron Zemo!  (Except Strucker makes more sense for the movies, but whatever.  We'll see whether he makes it out of Avengers 2 or not.)  While recovering from defeat and planning their next move, Bucky remembers Zemo (or Strucker) playing a part in his past.  Another flashback!  Zemo is a total dick and deserves to die!  Widow comes up with a plan, and Bucky agrees because he knows she's smarter than him.

Widow vs Widow!  Bucky vs Zemo!  Bullets!  Explosions!  Everyone dies except for any of the named characters!  Redemption!  Closure (mostly)!  Bucky has all his memories back except whatever would be useful for a future movie!  It's awesome!

Cut to Cap... punching things in a dimly lit gym.  In walks Widow.  She's all, "There's someone that would like to see you..."  In walks Bucky.  Tension!  But it's cool, they hug it out.  Buck's all, "I'm better now." and Cap's all, "That's great, but you gotta go.  Literally everyone in the world wants to kill you."

Bucky and Widow leave together, and no one ever mentions Hawkeye.

After credits: Nuke, heading to Africa.  Oh, snap!