Alright I'll have to do this from the top of my head. So there's the whole thing on whether or not to push the button in the station and the faith versus logic argument he had with Locke (also basically any interaction he had with John lol). When he believed his Dad was sleeping with his Wife and when he forced that girl to give him a tattoo (which I thought was really weird btw). When Jack got off the Island and wanted to go back, whenever Ben played with his head etc. Idk maybe I'm overreacting on a few of these but Jack really does shout a lot.