AngularJS: Best way to handle data from socket with ng-repeat

I think it's best if you send to the client new events only, not the entire list every time. You could add those events to an array and let ng-repeat render them. Here's an example using ngSocketIO, a simple SocketIO module I've created for Angular (the syntax won't be much different than the one you're already using, I guess):

app.controller('MyCtrl', function($scope, socket) {
    $scope.events = [];

    socket.on('someEvent', function(data) {
        $scope.events.push(data);
    }
}

And the markup could be something like this:

<ul>
  <li ng-repeat="event in events">{{ event.name }}</li>
</ul>

Now you can change any object of the events array and it won't be removed when the next event arrives. If the same event can be sent again (with new data, perhaps), then you could replace the array with a "hash":

app.controller('MyCtrl', function($scope, socket) {
    $scope.events = {};

    socket.on('someEvent', function(data) {
        $scope.events[data.id] = data;
    }
}

The ng-repeat expression needs to be slightly changed in order for it to iterate over a hash:

<li ng-repeat="(id, data) in events">{{id}}: {{data.name}}</li>

In this case any local changes to an event will be lost if the same event arrives again. If you want to partially update the local copy of if, you'll need to do it manually, perhaps by saving the parts you don't want to lose and restore them after updating the local event with the new data from the server.