My favorite is Rust
Join or battle other players—or attempt to go it alone—starting with primitive tools and weapons and advancing to firearms and massive bases. You'll have to contend with wild animals, hunger, and thirst, but this is a very PVP-intensive survival experience and your main threat will come from the dozens of other players on the servers. Rust is still experimenting with its formula—having recently removed XP and leveling, and now with its new component system, the game is evolving with weekly large updates.
Hurtworld
Very similar to rust, which is why I like it
Don't let its mildly cartoony look fool you: Hurtworld is no picnic. If you survive a few early hours of scrounging and combat with AI mutants and human players, you'll be able to claim land, build a base, and repair procedurally generated vehicles (if you can find the parts). There's an emphasis on the effects of weather, and not just on the player—for instance, the steak in your pack might freeze instead of rot when it gets cold enough. And, for a game that promises to punish you, it's surprisingly forgiving in a few instances, such as letting you keep your weapons when you die.
The Forest
After picking through the wreckage of the plane crash that stranded you here, you'll quickly discover you're not alone. You share a mysterious island with a tribe of terrifying cannibals, and while you struggle to stay fed and hydrated, build structures from simple tents to log homes, and construct traps to snare animals, you'll have to defend against the hungry and determined locals. The Forest is built in Unity 5, which provides stunning visuals and effects.
Now with Co-op, you and your friends can fear together, build together, hunt together, and most likely die together
This War of Mine
Depicting war not from the perspective of an elite soldier but from that of a group of civilians simply trying to stay alive amidst the chaos, This War of Mine is a different and more desperate kind of survival game. You'll face tough choices as you manage your survivors' health, both physical and mental. Scrounging for food and supplies during the night is tense and harrowing, and no matter what you find it never seems to be enough. It's not just a survival game but a harsh and unblinking look at the reality of war.
Ark: Survival Evolved
Dropped nearly nude on an expansive map filled with dinosaurs, you'll have to contend with extreme heat and cold, starvation and dehydration, and fellow humans (though you can play solo as well). Craft weapons and gear, build a base, tame and ride dinosaurs, and join with (or battle) other players. Ark's free Primitive Plus DLC adds tons more depth to crafting and farming, and the upcoming Tech Tier update promises to add sci-fi inspired weapons and gear.