One of Mrs. Wit's favorite liqueurs is Chambord, a french raspberry concoction that performs absolute magic on medium and lower quality champagnes. A splash of the stuff in some Cook's absolutely transforms it into a treat beyond reckoning.
When we drew this one from the deck, we were pretty sure what to expect. But we were not prepared for having a difficult time finding creme de cassis: we tried searching for it at no less than three good liquor stores, with no success.
It turns out it's fairly easy to find supermarkets. Go figure.
Chambord is better, but creme de cassis is definitely cheaper.