The Arma 3 mod, Exile, is an interesting venture into the survival genre. Featuring resource gathering, missions, and base building, there's a lot to do in Exile. There are lots of servers to choose from, and many will feature different maps and additional mods for those who get tired of the basics.
The focus of Exile is to survive, do missions, earn respect (exp), and perhaps build a base if you feel like it. The mod has a built in the economy of sorts, where the items you gather out in the world can be sold for pop can tabs, the mod's currency.
MOD EDIT: Removed link..
