I like hemp milk--it has a better nutritional profile than rice milk, but it is expensive. Check the level of sugar in the various brands. Some have quite a bit, others have very little.
I also like coconut milk. There are coconut milk beverages available, but you're paying for a lot of water and some calcium fortification. I buy the canned coconut milk (organic, BPA-free can) and dilute it 1 part coconut milk to 3 parts water to make a coconut milk beverage that we use as our standard milk substitute for cooking, baking, etc. This is less expensive, but there is no added calcium.
Having said all of that, I opted for extended breastfeeding with my kids and none of them have ever really accepted any milk substitute as a beverage.