I didn't really get the weighting of stories over time and finding stories sort of sticking around on page two and three days after rolling off the front page was a bit confusing coming from the Technmeme front page. I think what got me to sign up to make noise was the story about PG crashing the secret what-do-we-do-about-YC dinner for VC's...though it might have been the flatulence simulation iPhone app wars, since it was in days when HN rewarded snark and there were few higher internet pleasures for me than snarking on Apple to piss off its insufferable adorers. In the long run, HN allowed me to find an audience for writing on less lowest-common-denominator topics and pursue more interesting interests than upsetting apple carts.
Before Hacker News, I was browsing Reddit for interesting news but it quickly became unrealistic; the SNR was way too low and the comments not worth reading.
Hacker News is currently my site of choice for quickly finding interesting news that may not get coverage by other media. The comments generated are usually of reasonable quality and worth reading, something I usually skip on other sites.
Possibly intriguing backlinks from SO to HN.