Signal to noise ratio, in comments and in content both. I was a loyal Slashdot reader (and comment lurker) for many years before coworkers introduced me to HN.

Signal to noise ratio, in comments and in content both. I was a loyal Slashdot reader (and comment lurker) for many years before coworkers introduced me to HN. I was stunned with the high-signal qualities of the main page results--I almost never visit without reading multiple links off the main page. The selection of what is currently considered interesting by the mods/voting process fairly closely maps to interests of my own. I like, among other things, that 'old' articles and links are permitted, but signposted that they're not current. And yes, the comment threads are healthier than elsewhere, and the signal ratio tends to be high enough to be worth reading from time to time. I don't read comments every day, but I do read Ask HN posts from time to time, and on particularly current and relevant articles. Likely enough to find interesting discussion contributing to the topic to be worth the time reading. So yes, HN is one of my top visited sites now, and has pretty much completely supplanted reading Slashdot...I've gone from visiting ./ multiple times per day to looking it up once a month when I'm bored, just on the off chance they picked up something I'd missed elsewhere.