#proglangdesign and #osdev are some of my favorites on Freenode, otherwise it's mostly language-related ones.
#dragonflybsd on efnet is probably my favorite technology-specific channel. Lots of interesting stuff happens there (and sage wisdom from Matt Dillon).
If you go on the actual subreddit, you get bombarded with illusory superiority, google knowledge, and advertisers. I saw someone trash Apache server because it includes a test suite in the source package. I love the constant astroturfing for certain products. The best part is their "articles" where they try to make their job sound like a popular HBO TV show.
It's just not a great place to go for anything. The people there seem deeply flawed. They are trying way too hard to be the "intelligent ass hole" without the research.
Most of freenode is this way. You'll notice that freenode admins/ops will ban for any off-topic discussion and most chans are deafeningly silent because of this. It's a terrible environment for natural discussions.
I remember I used to chat in the WordPress chat. I was one of the few people who actually answered questions. For some reason there was an off topic chat. One of the regulars was ll "that's off topic - stop" I pointed out there was off topic there all the time. He then proceeded to make a point of that he chatted there more often. I pointed out that I had previous just changed the nickname I was using and to use my previous my nick for his wc -l command. 6 hours laters I was kicked and banned by ops. Fun fact, off topic wasn't against the rules. Telling people you're more important than them because the amount of time you've been there was. I was told I could go back in a few hours. I stopped going there and answering questions after that. That was the final straw for me and WordPress. I haven't used it since. Their bug trac was full of bugfixes that never got applied, got repatched and then still never got applied.
In other words, traditional old-school SAs who feel threatened by the general model of agile/"move fast, break things." The kind used to receiving code from over the wall, yelling only that it's shit, and throwing it back.
What channels / networks are people hanging out in?
I mainly lurk on ##re and ##security on Freenode.