The best way is to shoot them. You seem to live in a populated area and the deer are only going to cause problems if left unchecked. Thier numbers need reduced. A dog may be a good idea, but do you want it chasing after the deer and getting lost or run over by a car? Or if you tie it up do you want it barking all night and disturbing your peace as well as the nieghbors? Other than a very high fence around your property, you won' t keep the deer out for any length of time. Shooting them and reducing thier numbers will allow you to still see them sometimes, but they shouldn' t wreak as much havoc on your yard.