A lot of people are saying games. What kind of games do you use, specifically?
For me, it's not even particularly violent games that I vent with, like Painkiller. Pretty much anything I can become immersed in will help me calm down, so a game with good flow to it. Warframe is my current escape from reality. The gameplay is fast and dynamic, so it takes up all my attention, but it's not frustrating, plus I always have something I'm working towards. So I get the instant gratification of mowing down enemies and the sense of achievement that comes with earning/making something.