Allot yourself a certain time of the day to play them. Basically, schedule your play time and only play during that play time. That's what I do. I play at a certain time of the evening, for 2 hours maximum. Otherwise I don't really touch my games. If I'm doing something else at that time that I feel takes priority (such as working on something or doing something else with friends or family) then I'm probably just not going to play that night. That's basically how my friends and I helped get one of our group out of a gaming addiction: hanging around with his brother at their place doing other stuff. Over the course of a few months he slowly would come out and make his way closer to us or hang around in the doorway of his room watching us for increasingly longer periods of time, until he eventually would actually log off the game and join in our activities. We just consistently got together at the same time every week. Nothing more to it.