Cap, all day.
Even if we confine it to the movies I still side with Cap, but I do have a hard time seperating the shyt Tony pulled in the comics...the movie made the area a little more grey, if you side with Stark in the books you're a fukking scumbag and I hope your dikk falls off.
They'll all say Cap but forget who ended the movie as a fugitive and who ended the movie in control of The Avengers
One of the first things Tony did after signing the accords was break them...he even made a joke about having to arrest himself after going to do superhero shyt without a warrant.
But thats my more objective reason. On a personal level how can you not side with Ironman , unless you are literally a fatherless faggit that never knew your dad. As soon as you realize Cap been on stage all up trying to be all in the videos , acting buddy buddy with Stark for all this time with his gay righteousness while knowing who killed his Parents and have the nerve to have you help and support bucky. I would have had to murk them both. I know he was brainwashed but if you was Stark you wouldn't give a fukk either about that. Nobody likes being the fool to an inside joke.
Cap never saw the video or had confirmation. In CWWS Zola hinted at Hydra being involved in Howard Starks death but it never explicitly showing Bucky did it.
Even if he knew for sure I could see the rationale behind covering it up out of fear, even more so if it' basically amounts to a hunch. At what point was he supposed to strike up that conversation?
That's a reminder that Steve is human and like the rest of us can't always live up to our own loft ideals. That ain't got shyt to do with him feeling guilty and hand cuffing the rest of the team for his fukk ups without any compromise, especially when it's at the hands and under the control of a government that you can't trust.