I, like any other player, enjoy pwning the hell out of people. However, I also like to see my opponent's strength improve so it challenges my own more. To do that, I feel that a majority of the community needs to learn the three following skills:
1.) Patience- This is the number one trait that 95% of the WoW community lacks. In order to succeed at anything, you must be patient. Don't pull the General's room in AV until all towers and your graveyard has capped, no matter how close the enemy is to yours. Wait things out, and see what happens. Follow a game until the end, no matter how poorly it's going. And above all, learn to just wait. As a Rogue, this was one of the first skills I learned and it has served me well since level 1.
2.) Respect- Trashing an opponent is good, but disrespecting him isn't. I'll chew out any team mate I see using emotes such as /spit or /laugh on a horde, or I'll stalk down and kill any horde I see using that. It's ok to emote on someone (my all time favorite is /wink. Just cocky enough to **** em off, but not to the point of being disrespectful). If you learn to respect your opponents as much as yourself, you will not only be able to keep a level head while fighting, you will also be able to lose with dignity (no one can win every battle they fight, the world just doesn't work like that).
3.) Persistence- Never give up. Even if it's 1990/0 in AB, never quit fighting. You never know how the flow of battle will change. Quitting halfway through it only insures that you've lost.