It's very interesting to me that so many other people had the same experience with Digg and Reddit that I did. At first, I read it obsessively but now I can barely stand to scroll through the headlines.
HN has gone through a different cycle so far. At first I only read the front page because it had enough of content for me, but now I skip many of the front page stories and go directly to the "lost" gems on the new page.