Once a week is already a good basis. Maybe you can volunteer for a local association. Whatever it is. Helping at your local animal shelter, distribute free soup, red cross, local amateur radio station, or join a sport club (climbing, football, rugby, basketball, running, skateboard, whatever).
The thing is that your home time should be focused on real stuff. If you have full days outside, when you come home you don't have 8 hours to spend on the PC. You've got to clean the apartment and do laundry, prepare for the next day, cook/eat, and get a good sleep because you're tired from that full day.
The key is to spend little time at home, because if you've got a full day staying alone at home, boredom and lazyness will bring you to the PC again and to videogames.
Also from the activities mentioned before you'll meet people, new friends, and potentially a girlfriend. A girlfriend fills your schedule pretty fast. And if she's home with you you'll be busy enough not to play videogames ;)