Open World Multiplayer Game?

I am looking for an online, open world, massive multiplayer game for the PC, preferably on Steam. The idea here is that I want something that my friends and I can log onto, meet up, team up, and do stuff, and then when we're done, be able to save and quit, so when get back on, we're where we left off both in physical location and progression in the game. Does this make sense? I want it so my friends and I to be able to form somewhat of a "permanent team". Certain games that caught my eye were Day Z, State of Decay, and Mount and Blade: Warband. Do any of these games fit the bill? Any other suggestions?

Thanks guys!

Thats abit Counter Intuitive ? why would you want an Massive Open World game for multiplayer with your friends ? Wouldn't they just run off off and do their own thing instead of actually playing together, or wouldn't you all play together instead of exploring the world ?

Something feels off.

@TheBoxisHere: GTA Online does most of that- permanent teams(though you have to register with the Rockstar Social Club) it's open world, it saves your progress, and depending on how many people you can get online at one time, you can form a private match of up to 16 people.

There are missions, deathmatches, races, parachute jumps and depending on your level, ambientactivities like liquor store robberies, gang shootouts, armored car heists, and more.

To answer your questions: I want a a massive multiplayer that I can play with friends... because thats what I do anyway! I've played GUild Wars 2 (great game btw), and it's a lot harder than it seems to form teams on the fly. It is much easier to play with people you know. As for what I want to do... I definitely want something more Combat Based, but I want the game to be sandbox-y, not structured or linear. An example of a structured or linear multiplayer game would be games like League of Leagends, God Mode, or any of the Call of Duty games. I want a game where we can either band together and just survive, or amass enough team members to go harass some people. Does this make sense? I don't know why this request seems so suspicious! O_o

@TheBoxisHere: I'm telling you, GTA Online answers every description you just put together.