a 10 foot fence uphill with a moat.
dogs loose inside an electric perimeter but you have to fence the garden or the dogs dig it up
horses or goats who like to chase things but you need a really good electric fence around the garden to keep them out.
I've also heard big cat excrement, urine hanging in plastic bags (our zoo does a huge business selling it) and human bodily waste. This came from a guy with a big garden.
You can probably use alternating hot and ground wires and ten foot posts. Be sure your grounds are connected to a real earth ground so they work no matter how dry it is. If I remember correctly in Australia they have to use something like 5 hot and ground alternating because it's so dry. I have to use this technique for horses because sand gets dry so fast. 16 gauge galvanized is really good because if they do crash it, it's cheap and easy to fix and breaks without injuring the animal.
People love deer until they eat their new 50k landscaping, jump through a window and swim in their pool.