I regularly stock three cocoas- Green & Black’s, for things that absolutely need the perfect balance of chocolate with other flavors: cakes that enhance chocolate with nuts, the shiny glaze from RHC, etc.
For cakes that are straight chocolate and I want a little stronger chocolate flavor, I love E. Guittard’s cocoa rouge (which is full fat- 23%, I checked with the company). This is the cocoa I often use for the RHC deep choc passion cake, where there’s no butter to intensify the chocolate and I want a deeper, perhaps slightly bitter but complex cocoa.
And for Genoise au chocolate, I actually like to use Equal Exchange, which is a low fat cocoa, because it gives what is normally a fairly mild cake a stronger flavor than the full fat cocoas. This is also my choice for kids’ hot chocolate.
The Bensdorpf from King Arthur also works well, though I don’t like the flavor as much as Guittard, which is a close second to G&B.