d20, followed by the d12. They roll better than dice with fewer sides, and they're more versatile: you can use a d20 as a d4, d5, or a d10. And with the d12 you also have a d3, d4, and d6. Combine both in a matrix to get a d8, d24, etc. And by themselves they have a wieder range of possible outcomes than the rest of the (usual) dice.
I don't like any dice that aren't based on platonic shapes, e.g. the d10. It's simply unnecessary to have them when there are so much better replacements.
I don't like any dice that aren't based on platonic shapes, e.g. the d10. It's simply unnecessary to have them when there are so much better replacements.