Cannabis Sativa

Rather than doing drugs you should just repeat this simple mantra:

You are not special, you deserve nothing, and you aren't particularly good.

That's all I ever do for myself and I'm p-happy with life in generally. It's when I start believing that I deserve better than what actually happens that I get angry.

Just rage scream like makaveli

This might sound strange, but a great solution is to swear.

http://www.scientificamerican.com/article.cfm?id=why-do-we-swear
http://www.forbes.com/sites/frederickallen/2011/04/21/use-foul-language-to-relieve-stress-and-pain/

As long as your mic isn't on (and you have understanding housemates/neighbors), there's no downside to relieving stress through a well said "FUCK".
You're releasing the stress, so there's nothing pent up, but you avoid any possible property damage.
Barely cheaper than a stress-ball, but you can keep your hand on the mouse while doing it.
EDIT:

Beat me to it haha

this has also been effective for me, you stop expecting and you start learning what you can do to reach what you want to be

drugs are a temporary solution and they tend to mess you up more if you're not entirely stable minded

stativa is a energizer indica is the relaxing one

If you're constantly raging at a video game it's likely not specific to video games. If you feel like you are a calm person outside of video games...just wait till you get married or in a long term relationship. Those anger issues you experience playing games will crop up, haha. As to how to help address it I think it comes down to achieving emotional awareness. I remember back in high school just taking a basic psychology class - the mere practice of studying how our brains process things helped me become more aware of when a strong emotional force was pushing me to react a certain way, and it helps allow me to identify those situations and kind of 'step back' from that moment. I do get annoyed in video games and frustrated, but I feel like ever since studying that long ago it helped enable me to intercept it at a certain point, take a step back and re-orient myself to the situation from a different perspective.

It's kind of crazy that the brain is capable of being aware of when the brain is leading you on :)

Mostly it's about making a conscious decision on how you want to live your life. People are going to do things that your natural inclination will perceive as malicious, or rude, or manipulative, 99% of the time those people have no idea that they are offending you at all. Unknowingly you are doing the same thing to people week to week.

I know people that go through life ALWAYS angry about something, or always angry about some personal relationship. It's absolutely exhausting and it never ends. At some point I would think they should realize that the only common factor in all of those engagements is them. You are going to be slighted, people are going to do things that will irritate you, BUT, you always have the choice of how to react to something, don't be at the mercy of your emotions.

P.S. My wife gets pissed off how calm I am.

Also I recommend reading books that have a philosophical slant to them. I read 'way of the peaceful warrior' my first year of college and still carry lessons with me from it to this day.

whatever you do, don't take it out on your $100 keyboard :(

You can't really care about the game and not get mad when things go bad. But I had this rule: it is fine to rage, just don't press your push-to-talk key for mumble. If you get mad and you rage in mumble you are just going to affect the team dynamic.

Headbutt a child.

Go over the top sometimes for no reason jokingly, that usually helps me.

the only person letting you get mad is you. everybody else ingame, including your teammates or your opponents, are external factors that should not have any impact on how you feel. make a conscious effort to avoid bad stimuli in your play environment or get into a ritual where you play on certain terms that you won't get that mad and try simple things to redirect anger -- slam your first on your bed or pillow, turn on chill music, drink some hot tea while you play. challenge yourself to do so -- it's much easier to discuss than to put into action your words.