I keep up with current events mostly through a couple of very popular niche forums, each with a few hundred thousand members. The news posted there is biased, of course, but mostly it's a selection bias. I use it because my interests (if not necessarily my perspective) overlap with those forums' topics. When I find something that piques my interest, then I'll seek out other sources for that particular story.

I spend the majority of my "what's going on in the world?" time on ar15.com - but I don't assume that the stories posted there are accurate. I judge the reputation of the source from which it came, and if it's contentious, I'll purposefully look for alternative reporting.

The bottom line is that no news outlet, "mainstream" or not, is without bias. There are decisions made on what constitutes news and stories are editorialized both explicitly and implicitly.

There was a time when I spent a decent amount of time on 4chan, but the SNR is so low these days and the format is so hard to keep up with that I haven't bothered in years. Instead, I watch secondary sources who are watching the chans.