5. Coulson Confronting Loki (Avengers: Assemble)
Bless him. Everybody loves Agent Phil Coulson, but he might as well have committed suicide given his actions in
Avengers: Assemble. When Loki had tricked his brother Thor in to locking himself in the Hulk-proof cage aboard SHIELD's helicarrier, he was about to press the button to drop said cage 30,000 feet towards the Earth. He was interrupted by Coulson, who calmly uttered the words "step away, please" whilst wielding an experimental and dangerous looking weapon that SHIELD had crafted using the Destroyer Armour. Of course, Loki always had tricks up his sleeve and, following his killing spree of 80 people, he didn't hesitate to use his powers to trick Coulson, appearing behind him as if by magic, and stabbing him all the way through his torso via his back. As noble and brave as Coulson showed himself to be in doing this, confronting Loki (essentially a god in comparison) was a very bad choice for a human being and he suffered to consequences gravely (but, as we all know, it doesn't appear that he's really dead - thank goodness).