I play a video game. Evolve helps, since I have friends online that I can talk to and have a good time without dealing with real life stuff.
If I’m having a really bad day, I play something offline. Mirror’s Edge, Skyrim, and ACIV/ACR are my picks for that (Would not recommend XCOM- Your rage will manifest itself nastily).
Of course, music helps.
Sometimes I just stay up until 2 in the morning or something for no reason other than to watch a movie on netflix or internet videos. I would game, but I have a family that doesn’t get that playing video games until 2 in the morning on a Friday night is good for me :P.