I am lactose intolerant and cannot stand most of the milk substitutes. I have found a product though that is great. No chalky taste that you get with the Lactaid milk. It tastes the same. It is unfortunately a bit pricier but since I have been rather turned off from drinking milk it doesn't end up being a real drag on the budget. I use it on cereal when I have it and also use it in cooking and baking, it works quite well.
Deans Easy Milk, I usually buy the fat free version personally.