NEO Scavenger is a turn-based, roguelike scavenging game. I like it a lot, because it's gritty, fairly in-depth and more realistic than almost every other survival game.
NEO Scavenger first asks you to choose your perks/flaws: Botanist, Strong, Myopia, etc. There are no XP and levels, so, mostly, what you see is what you get. After selecting your starting skills, you are thrown into the game barefoot and with only a hospital gown.
Your first order of business is finding the basics of survival: shoes (one left and one right!), warm clothes, a lighter, a crowbar for scavenging, a sleeping bag, tools to obtain clean food and water and something to carry all this stuff around. In fact, the very first treasures you'll scavenge are probably disposable plastic grocery bags. They're very fragile, but they're tiny, weigh nothing and will serve as your first backpack. Those bad boys are little life savers, you have to love them! We should probably produce and dump more plastic bags all over the place for fututre survivors, right now. What do you think of that, environmentalists?
From then on, you'll also need to find all the other things you need to survive: clean rags for wounds, alcohol for disinfection, antibiotics, painkillers, a firearm with ammo, gloves, a gasmask for polluted areas, crafting tools, binoculars, noisemakers to warn you of intruders during the night, etc. One of the game's main qualities is that the list of things needed to survive effectively is very, very long, but you can also make do with just the essentials.
Contemporary technology is surprisingly useless. A found computer might have no battery, then a found battery might have no charge in it, then a charged battery will reveal the computer is password-locked, then you'll hack it (if you picked that skill)... only to discover the computer only contains pictures of cats. On the other hand, a cheap plastic bottle filled with safe drinking water is always a useful commodity. Is that social commentary or what?
Weapons are also imporant, but not nearly as much as in most survival games. It's possible to completely avoid all combat with a peace-loving build.
Speaking of which, combat is a strange numberless affair, where you choose broad actions (run forward/back, take cover, trip enemy, threaten). The only numeric value is range, which is enormously important depending on your fighting style. What you do get are surprisingly graphic descriptions of your situation: "You have passed out from unbearable pain" or "You have died from acute bleeding to the lungs". Ouch. As in real life, he who strikes first usually wins. It's also possible to win a fight and die from your injuries not long afterwards. All in all, fights are terrying (as they should be), the results are sometimes unpredictable and fighting fair is always a stupid idea. Did I mention you can be killed in your sleep (and vice-versa)?
There's also crafting, there's always crafting. Except here it's realistic. You're not going to craft an assault rifle with rocks in NEO Scavenger. In fact, a good ol'fire is probably the number one recipe. Sorry, no fire by friction if you haven't chosen the Trapper skill at character creation. Making fire without an external source is really not that easy without training. Another essential crafting recipe is: Fire + Water + Receptacle = Boiled (sterile) Water. Don't tell me it's boring until, weakened by diarrhea from drinking dodgy water, you are punched to death by a hobo. By the way, the game doesn't tell you what makes you sick: you only know you messed up somewhere when symptoms start showing up.
The game leaves the player with three general survival strategies: use nature's gifts to provide for your needs, scavenge cities for pre-apocalypse technology or... murder every survivor in sight for the contents of their shopping bags, RAWR!
The game has a main storyline, but as of right now it's pretty short. And did I tell you THIS GAME HAS NO ZOMBIES? Yay!
The game has two main flaws. First, the game could do a better job helping you find points of interest. The map is very large and it's not obvious where the important areas are. The second is almost a praise: I want more of it! I want more items, more weapons, more unique areas, more special encounters, more animals. MOAR! The possibilites of common household items having ingenious survival uses is almost endless. Variety in this game is good, but not great, but things are still being added to the game (and there are mods).
While I recommend NEO Scavenger, it is in Early-Access at 99% complete, so it might be worth waiting a bit if you want the best first experience possible. Yet even right now, it's still a pretty great game and an impressive achievement as the work of a single man.
In conclusion, I'll quote Rock, Paper, Shotgun's Graham Smith which sums up the game's worth pretty well:
"NEO Scavenger is the only survival game that feels like it has anything to do with survival."