I have tried several different things, but I think this one's my favorite...
1 cup milk heated VERY hot
2 level teaspoons unsweetened cocoa powder (I've tried Hershey's and Tollhouse, loved them both)
1 generous squirt of vanilla syrup (you can find in the coffee aisle of most grocery stores)
2 TBSP coffee mate coffee creamer
Sugar/sweeten to taste
Heat up your milk (I pop mine in the microwave). While it's getting nice and hot, combine cocoa and vanilla syrup with enough water to make it liquidy (add water slowly, too much is not good). When milk is hot, stir well, add in cocoa mixture, creamer and sweeten to taste...YUMMY. Oh and I have used cool whip instead of creamer, whatever you have on hand.