Soy milk is great for the lactose intolerant, as well as for those looking for more lecithin and vitamin E. It is considered a good choice for women as it contains isoflavones that are believed to fight cancer, heart disease, and to have a beneficial effect on menopausal symptoms. For taste, however, it is not the most popular.
Rice milk is becoming more common lately, and therefore a bit cheaper, although it is still usually more expensive than soymilk. It is a good choice for people who are allergic to soy products or simply don't like the taste of soy milk, but if calcium is a consideration stick with the enriched rice milk. It is lactose free, but it is also much lower in protein than cow, goat or soy milks and the carbohydrate content could be a problem for some dieters. Rice milk usually does well in taste tests.
Oat milk has many of the same vitamins and minerals of cow's milk without the lactose and with the added bonus of fiber. For those who are sensitive to gluten, it also comes in gluten free. Most people like the taste, and oat milk has yet another benefit as studies have shown that it can reduce cholesterol. The only drawbacks might be the price, availability and the lack of folic acid.