A few tips on etiquette in gaming

I'm not Polite Polly, and I'm not Ms. Manners, but I'd like to help you anyway with your game etiquette. Playing games can be frustrating at times and you can become angry, but that doesn't mean that you should express your anger in the game.
What you read here should give you the chance to still have fun, while not ruining the mood of others during a multiplayer game.
1. Make sure you encourage the other players. Even in a game where you compete against each other, like in a car race or a fighting game, make sure you invest some time and give the other players congratulations when they do something cool, like a great move or taking a smooth curve. I'm not saying you should kiss up to him, but don't leave tensions build up between you. You're playing a game, so have fun and make sure others have it as well.
2. Have some patience. The people you're playing with might be less coordinated, smart or fast than you are. Just because your game slows down because of him, don't start criticizing. You can try helping them out or just plan the next thing you need to do. Cooperate a bit and that might give you a less stressful game.
3. Take a break from time to time. If the game has areas where you can pause from time to time, do that. Go eat a snack, stretch, go to the john, watch a silly commercial or talk about school. Playing all the time without taking any breaks can get stressful or tiring.
4. Include everyone in your game. What I mean is that the other players should contribute with their own efforts to the completion of the game. Make sure they enjoy the game and feel the same sense of accomplishment as you when the game is finished.
5. Make sure you listen to what they have to say. You're not perfect, nobody is, so it makes sense listening to other people's opinion on how the game should be approached.
6. Get the weird guy to play too. I know it sounds weird, but remember the massacre from Virginia Tech. A lot of people remember that the guy responsible for it was bullied by people since he was little. A simple effort of playing a game with someone might give him the kindness that he needs from others. Not saying that you're going to prevent murderers from doing stuff like that, but you should try to be kind with people and invite them to play.
7. Try to curse as little as possible and talk with a low voice. Don't go into arguments with those that you play with. Agree from the get go to be civil in your discussions about the strategies that need choosing. In many cases people will fight about something silly and that's just not worth it.
You can do all the things mentioned in this list easily. Trust me, it will help you enjoy your games more and the same goes for those you're playing with.