I love good dystopia. I love reading fun thought experiments where something gets tweaked in the society in an interesting way--banning books, subjecting everyone to the thought police, altering human reproduction in some way--and then we see where that society goes. A good dystopia, in my mind, is one that sheds light on our current society by changing some fundamental and then putting us readers in the position of empathizing (or at least following) someone who has grown up with that fundamental.
I'm not going to list all my favorite dystopian literature, but I am going to say "Birthmarked" is getting a spot on the list. It's about a young girl, Gaia Stone, who is a midwife. As a midwife she's expected to hand over the first three babies she assists in the birthing of to the enclave--basically the walled-off upper eschelon of the society. She has no reason to question this practice. It's well-known that kids inside the enclave live lives of relative luxury, with access to education, better food, and better medicine than those outside the walls can afford. Her older brothers both went to the enclave. She, however, was scarred by and accident with hot wax when she was young and so she wasn't picked to be 'advanced.'
Shortly after she delivers her first baby to the enclave, she discovers her parents have been arrested and taken to the prison inside the enclave. She, of course, has to get them back so she sneaks in, just in time to watch the execution of a very pregnant woman. Gaia convinces the man responsible for disposing of the body that she's a relative and quickly slices open the woman's belly, saving the child but landing in prison. From there she slowly unravels the mystery of why her parents were arrested and why the enclave wants the babies in the first place.
There are a number of reasons why I love this book. First, it is a well-told story. I didn't ever want to put it down and was always anxious to pick it back up.
Second, unlike many science fiction dystopias there weren't any egregiously bad science details for me to get hung up on. This could as accurately be classified as a science fiction novel and the science in it is good. There's no magic science allowing people to control others or know things they shouldn't be able to know.
Third, human life is valued within the framework of the story. One of the things I dislike in many dystopias is that human life is considered worthless, or at least very cheap. That attitude is so thoroughly divorced from my experience as a Western person that I have a hard time accepting it. Sure, under extreme situations those of us raised in the western world would have the potential to treat (some) human lives as expendable, but not as an every-day thing. I think the suicide rates and prevalence of PTSD and other psychological disorders among our combat veterans speaks to that strongly. When you're raised with the idea that human life is sacred, living in a situation in which human life is suddenly completely expendable does serious psychological damage.
With the possible exception of the Hunger Games trilogy, that theme isn't even hinted at. It's just assumed that once society descends into chaos human life will become cheap and will forever stay cheap (Margaret Atwood, I'm looking at you). I simply don't think that's realistic. People raised with a western mindset will reassert the value of human life once some measure of stability is possible again. People are too big an investment, even if you don't educate them all that well, to just throw to the meat grinders.
Lastly, instability doesn't last all that long, certainly not decades. Humans, flexible as they are, like stability and will work--hard--to create it. I'm concurrently (sort of) reading Rob Ziegler's "Seed." It's hard to know how long the conflict in that story's been going on, but it sounds like people have been on the move, dealing with serious ecological disasters for decades. That's simply not realistic. Yes, people have been nomadic in the past, but with much smaller population densities. If we returned to a nomadic lifestyle, even if it were a sort of itinerant farming kind of lifestyle, human population would drop to the level that would be supported ecologically within a few years at most and you'd stop having mass starvation all the time. Droughts, floods, or other disasters would occasionally stomp on the remaining human population, but those events wouldn't be yearly. So, yeah, the image of starving farmers drifting zombie-like across the plains is heart-wrenching and frightening, but not realistic.
Far more realistic is the image painted by O'Brien: a smallish city, isolated, but eking out an existence based on locally available resources and the remnants of technology preserved by the (now) upper echelons of the society.