With the eventual release of Origins this summer, it is time to revisit my idea of a Core Set cube. I would include Tenth Edition to stick to Black Border Modern, and then, of course, M10, M11, M12, M13, M14, M15, and Origins.
Here are the mythics I currently have.
And here is a picture showing also the ones I do not have. I am not showing the rares because there are way too many of them. The metric for how well filled this cube is has to be about the mythic rare coverage.