I was wondering about the opinions of the dopers on Getting Even. My personal system for deciding whether or not to seek revenge is a variation of tit-for-tat. If someone wrongs me, but gives no indication of wronging me again, and I have something to gain by letting the issue slide, I usually don’t worry about it. On the other hand, if someone wrongs me and gives no indication that they won’t do it again, I get pissed and stay that way for a long time. I don’t consider this particularly moral, but it’s carried me this far without either people taking my stuff without fear of retribution or me being in jail for killing someone who cuts me off in traffic.
Can someone suggest a scheme for forgiveness/vengeance that works better?
Do a google on the iterated prisoner’s dilemma for more than you wanted to know about this topic.
For me, it depends on who pissed me off, and what kind of mood I’m in. If a friend wrongs me, and I believe that afetrwards he’s legitimately sorry, I let it slide. If someone is rude to me in a store, I ignore it. If it’s someone that I don’t like, however, I probably won’t stick with getting even, I’ll make sure I end up ahead. Within the boundaries of the law, of course. 
And of course I keep my own best interests in mind. If revenge is likely to be against my interests, I’ll begrudgingly let it slide, at least for the time being. However, I do have a short list of people I’ll have deported to oppressive communist nations after I take over the US by bloody coup and establish my dictatoship.
Jeff