NG Option test
HTML
<div ng-app="app">
<div ng-controller="TestCtrl">
<select ng-options="item as item.label for item in items track by item.id" ng-model="selected"></select>
{{selected}}
</div>
</div>
JavaScript
angular.module('app', [])
.controller('TestCtrl', function($scope){
$scope.items = [{
id: 1,
label: 'aLabel',
subItem: { name: 'aSubItem' }
}, {
id: 2,
label: 'bLabel',
subItem: { name: 'bSubItem' }
}];
}, ["$scope"]);