Hanging a plasma tv what size anchor bolts?

I believe what you need is not a bolt, but screws that are thick and are made in high quality. Micro fasteners (http://www.microfasteners.com/) sells a lot of fastening accessories like different kinds of screws, drilling materials, washers and many more. Visit their facebook page facebook.com/microfasteners and don't forget to like their page too! Hope this helps! :)