Generally speaking any thread, log or solo log with Bucky is going to be one of my favourites, so instead of trying to narrow it down I'll pick the classic answers and mention the microwave feud, Call of Duty being inaccurate, and the Mets not being a real team. He was also a fantastic enemy for the Major.

Also 'Yelena's' steadily-escalating sequence of impossible badassery during the Iron Crown op was magnificent. So was that time she non-violently shut down a whole police force during the Mexico mission.