"Fifteen Million Merits": This one probably hit the hardest, because that is Corporate America. People are doing work that is fundamentally useless (the energy they'll produce, on these bikes, is less than they'll consume in food) to be kept busy for no clear purpose, and the ultimate conclusion is that those in control just enjoy the exercise of power. (See: the humiliation of Abi Khan.) This is most terrifying and poignant because the in-app-purchase existence is actually a plausible future of corporatized consumer capitalism.
"White Bear" and "White Christmas", two episodes both invoking the concept of human-created hell, are brilliant because they show an overblown sense of mob justice. In White Bear, the woman doesn't remember the crime and has been tortured and memory-wiped beyond recognition, so she's essentially not the same person who committed it and effectively innocent. In White Christmas, the most disturbing and bizarre thing about the end is that it's not the criminal, but a copied consciousness that did nothing wrong because it didn't exist when the crime occurred, the one created for the interrogation, who suffers in the "1000 years per minute" auto-hell. The actual criminal just spends Christmas in jail.
"National Anthem" is brilliant but hard to evaluate for plausibility because the U.S. doesn't have the same class system. We have severe inequality, but no one would fault a U.S. President for choosing not to fuck a pig at the risk of Kim Kardashian or Paris Hilton. Still brilliant, and an interesting take on the Streisand Effect (if he chooses to fight the publicity, he increases it, and the image of him fucking a pig can't really be erased). I also like the dig at "modern art" because most of it is trolling. [0]
[0] Actually, there's a lot of great art being made, even now. The problem with "modern art" is that there's a weird inversion where the gold remains obscure, and absolute junk sells for millions to rich people, because "making a statement" has taken more value than craftsmanship and aesthetic value in that joke of a scene.
"Entire History of You" kinda defeated its own point, if you ask me. His wife actually was unfaithful and he figured it out. Sure, it was emotionally unpleasant for him-- no news there-- but would he have been better off not knowing and raising that douchebag's kids? The main plot one wasn't really about the perils of technology. The moral was, "Don't marry a cheating harlot", but that one's over 9000 years old.
"Be Right Back" I found to be a luke-warm exploitation of the uncanny valley. I can see why that episode would appeal to people, and I won't say that it wasn't well done because all of these have been excellent; it just didn't hit me.
"The Waldo Moment" I found hilarious because I enjoy crass and obnoxious humor as much as anyone. That said, the ending wasn't plausible. People develop an immunity to that shit over time. It could unseat one political candidate, sure, but Waldo would lose its punch and its extortive capabilities. Mockery has power, for sure, but eventually people learn to tune it out. Not plausible to its full extent, but still poignant, and a bit funny for the sheer obnoxiousness ("breaching experiments") and stupidity of the Waldo character.