Slashdot, if you don't mind a heavy dose of Internet Meme along with your Interesting Discussion.
There are also sites which focus more on specific topics... if you're into server-side Java stuff, there's http://theserverside.com, if you're into programming language research, there's http://lambda-the-ultimate.org, etc., etc.
And a lot of the more niche subreddits are actually pretty good. Stay away from /r/funny, /r/politics and the other "big" ones and check out /r/machinelearning, /r/compsci, /r/systems, /r/math, or /r/compscipapers, etc.
Slashdot is ad-plagued and not at all the techie site it once was, IMHO. You used to get the big names in the field discussing their topics on there. Now it's mostly fanboy flamewars.
It's definitely not the same site it was in 1998, that's for sure. But I've (for whatever reason) been finding myself wandering back over there more and more lately, and I've been surprised to find there's still some good discussion to be had, but - as always - you have to pick around the GNAA stuff and the "In Soviet Russia" stuff or whatever the meme of the day is.
It's really too bad, in a way, that the founders of /. didn't take a more aggressive stance towards eliminating the silly bullshit. That used to be my absolute favorite site on the 'Net, back in the day.
I switched to here from Slashdot but I still read it the way I always did: via a newsletter. I just skim over items that I already read on HN. Its also useful if I miss a few days and feel like catching up (Yeah I know about Hacker Newsletter).
The level of discussion though is much better here.
There are also sites which focus more on specific topics... if you're into server-side Java stuff, there's http://theserverside.com, if you're into programming language research, there's http://lambda-the-ultimate.org, etc., etc.
And a lot of the more niche subreddits are actually pretty good. Stay away from /r/funny, /r/politics and the other "big" ones and check out /r/machinelearning, /r/compsci, /r/systems, /r/math, or /r/compscipapers, etc.