I like the Silk brand of unsweetened almond milk. I agree with Ange Says Rawr, the Almond Dream isn't as good.
Nut milks are super easy to make. You just soak raw nuts and then blend them. Cashew milk is yummy. Especially with a vanilla bean added. You do need a good blender to use the vanilla bean though.
All that said, I have no idea how any of these would be in coffee. I prefer my coffee black and from a French press. I'm a coffee snob!