Hemp milk and coconut milk are my favorites.
Both have better nutritional profiles (IMO) than any of the others in terms of healthy fats. Both also act more like milk in baking/pudding, etc than any of the others. Be careful with Hemp milk as the amount of sugar added varies wildly among the brands. I like vanilla flavored w/o too much sugar added to it.
Our go-to milk sub is coconut milk. To save money (and avoid sugar), I buy native forest organic coconut milk (in BPA free cans--I buy from Amazon--also in the Asian section of the grocery store) and dilute it 1 part coconut milk to 3 parts water, blend briefly and . . . voila . . . coconut milk beverage. I use undiluted coconut milk in place of evaporated milk, whipping cream, etc. It makes lovely cream soups as long as you add enough salt to counterbalance the coconut flavor.