One of my coworkers recently bought a Keurig coffee machine for our lab at work. He also bought a variety of K-cups. So far, I have tried two of the flavors. I have enjoyed several cups of Caramel Vanilla Cream from Green Mountain Coffee. I do not think that the vanilla and caramel combination is quite as good as plain French vanilla, but it is much better than the combination of butter toffee and coffee.
I have been trying to cut down some on consuming caffeine, so I tried a cup of the decaffeinated version of Donut House coffee which is also by Green Mountain. I think decaf coffee is somewhat pointless, but the Donut House brew was quite drinkable.