When I got bored with regular hot chocolate, I amped it up with cinnamon (and caramel).

What sucks is that my roommate does most of the cooking for the both of us (I can cook sorta, but really need a recipe handy, while he can freestyle) but he almost hates to use cinnamon because of how fast it can overpower other flavors. So when he does actually use it it's like a rare treat.