Tony
He plays with his miniature toy cars that he never even let's you touch because they are "collectibles, they are not for play Y/N."

Steve
He watches the Lion King and cries, then he watches Toy Story (all of them). After that he takes a nap while munching on Jellybeans (how he manages to do both at the same time? No one knows...)

Bruce
He does science most of the time but when he isn't he is bonding with the rabbit while making macaronid.

Pietro
He sleeps. Not normally though, he just drapes himself over something (the fridge) and passes out. He uses a lot of energy with you and never wants to miss a minute with you so once your gone he is out like a light.

Bucky
He goes to the park and just sits, sometimes kids would walk up and asks to touch his arm and he would hesitate and then let them. That then would evolve into Bucky becoming a living jungle gym to all the children, he never admitted it but he really was fond of children.

Thor
He walks around the house shirtless and swings his hammer around all fancy yelling, "I AM THOR ODINSON OF ASGAURD AND I AM SWAG!"

Clint
He sits on a little loft hidden in the vent just staring at the blank TV. I have no idea why. Either that or he will play hide and seek with Baby and crawl through the vents waiting from her to find him.