ABC News and Rathergate. Fake news, through and through. Dan Rather still claims the story is true, even though everyone knows it's a fraud.
Dateline NBC and the exploding truck. They couldn't get the supposedly dangerous truck to catch fire, so they rigged it with an igniter for the camera. Yeah.
NBC News and George Zimmerman. They took his 911 call and edited it to make him sound like a bigot, when it showed nothing of the sort. Read up on it, and wonder how much of what you "know" about that case is actually true.
When the Ferguson shooting happened, a common slogan was created because Michael Brown supposedly said "hands up, don't shoot." The trouble is that only one person claimed to have heard him say that - his accomplice. The many actual witnesses heard nothing of the sort. Yet the mainstream news organizations ran with it, and the (much later) retractions have been, to say the least, understated.
There are dozens and dozens of such stories, with the big difference being that they're held up as "journalism" by millions, while the fake news you get from Facebook is usually only seen by thousands at most, and almost always has someone pointing out that it's faked in real time.