I don't keep track of such things but, unless there is a sporting event I don't want to miss, I often don't turn the TV on for days. I still use it to watch my DVDs though (even if I do forget to write a review after!).
When I ordered the internet they offered me basic cable for an additional $5 a month for a year - I turned it down. The shows I wanted, ESPN and ESPN 2, were on the next available tier which was an additional $45 a month - forget it.
I remember when cable was brand new and the idea was you paid for cable because there were no commercials. Now it is no better than regular free television. And for $45 a month in savings I can buy a season or two every month of any TV series I want. And I don't have to watch commercials!