If I had a test kitchen right now, I'd be experimenting with chocolate covered coffee beans. They taste good, but the chocolate and coffee hang together like a subject and an object waiting for a verb to show up so that they could be a complete sentence. The chocolate and the coffee bean need a a creamy component, something that would smooth out the rough texture of the bean and help the flavors play together. Right now they taste good, but it's more like they are stepping over one another as if they are fighting to play on the same slide. The chocolate has all the fat and sugar, leaving the coffee bean a bit harsh and unhappy.
It could be as simple as dipping the bean into a bit of caramel or nougat first and then covering in chocolate. These are time tested ingredients after all, and I'd probably try them first. But I can imagine having some real fun trying all kinds of different things- like a mango flavor, for instance. Crazy flavor combinations usually fail, but they fail gloriously, and when you are done tasting everything, you have had an experience very few on the planet ever have had.
When I was quite young, I got my mom to make a lemon cake and cover it with "icing" made of peppermint patties for my birthday. Chocolate, peppermint, and lemon! I don't even remember which year it was, but I remember that cake! It was pretty good, but to my knowledge none of us ever attempted to recreate it. Perhaps I will one day- I'll probably think it's too sweet now.