execThen

app.html

<div ng-controller="UserCtrl">
  <p>Hello {{user.get_title()}}</p>
</div>

<div ng-controller="ListsCtrl">
  <p>All lists:</p>
  <ul>
    <li ng-repeat="list in lists">
      {{list.get_title()}}
    </li>
  </ul>
</div>

<div ng-controller="SiteUsersCtrl">
  <p>All users:</p>
  <ul>
    <li ng-repeat="user in users">
      {{user.get_title()}}
    </li>
  </ul>
</div>

app.js

app.factory('ctx', function ($q) {
  var ctx = new SP.ClientContext("/");
  ctx.execThen = (function () {
    var q;
    return function () {
      if (!q) {
        q = $q.when().then(function () {
          return $q(function (resolve, reject) {
            ctx.executeQueryAsync(resolve, reject);
          }).then(function () {
            q = null;
          });
        });
      }
      return q;
    };
  })();
  return ctx;
});

app.controller('UserCtrl', function ($scope, ctx) {
  var user = ctx.get_web().get_currentUser();
  ctx.load(user);
  ctx.execThen().then(function () {
    $scope.user = user;
  });
});

app.controller('ListsCtrl', function ($scope, ctx) {
  var lists = ctx.get_web().get_lists();
  ctx.load(lists);
  ctx.execThen().then(function () {
    $scope.lists = [];
    var e = lists.getEnumerator();
    while (e.moveNext()) $scope.lists.push(e.get_current());
  });
});

app.controller('SiteUsersCtrl', function ($scope, ctx) {
  var users = ctx.get_web().get_siteUsers();
  ctx.load(users);
  ctx.execThen().then(function () {
    $scope.users = [];
    var e = users.getEnumerator();
    while (e.moveNext()) $scope.users.push(e.get_current());
  });
});