The solution I provided in my answer above (using Node View Permissions) gives access per content type and not per node. If you want permissions per node you can have a look in other modules that enable that kind of permissions. You can find a discussion about it in this thread.
In my opinion giving access per content type is cleaner because you know exactly where you have given permission and where not.
You can do that by visiting /admin/reports/status/rebuild
Konstantinos