Combo: Capital and Herbalist
|Capital / Herbalist|
|Set(s)||Empires / Alchemy|
During your clean-up phase, discard the Herbalist first, putting Capital back on top of your deck. Now you no longer have to discard the Capital from play, and therefore do not incur the Debt penalty - allowing it to be used effective as a double Gold with a +Buy - plus it's top-decked so you get the Capital next turn as well.
This can be played for example as a pseudo-Golden Deck strategy, by acquiring multiple Herbalists and a single Capital and lining them up. Ideally, every turn you re-draw your Capital, and at least one of the remaining four cards is a Herbalist and another one of your starting Coppers, allowing you to buy a Province Debt-free and restore the Capital.