Hot chocolate (you can add whiskey to make it stronger)
Irish cream mixes well with it.
It depends on what you have on hand and what you're willing to buy, but I like to keep it simple.
Kahlua and creme. its awesome. also throwing it into ice cream mixes before you make them. kahlua in french vanilla ice cream mix is also really good.
Hot chocolate is FABULOUS with Kahlua, I agree :D
Milk with Kahula is devine.