Probably The Winter Soldier by a hair. Probably. It's so close between that and Civil War. Both fantastic movies.
__________________ "Your mother was a venereal disease-ridden prostitute who was raped by the father you never knew and killed herself when she saw what an autistic phaggot you are.
So what about my comments made your ass so sore? Was it me calling you a phaggot? I think not." - Nemebro
Definitely Civil War for me, but WS was great too.
Reasons.. Great development to the character arcs of Steve and Tony which began in Phase I and has evolved since. They started with an opposite take on things, both have done a 180 degree turn, leading them to be further apart than ever. And for all that to lead to them just beating the crud out of each other.. Loved it.
Was also a great continuation to WS and Age of Ultron.
And the airport action sequence was the best action sequence in comic book movie history IMO. And.. Spider-Man.. So good to see Spider-Man and Giant-Man.
Picked TWS, but honestly, it depends on the mood. Civil War has a lot of amazing action scenes, Crossbones done right and great many characters in it, all actors performing well.