Here's a great pack with 204 materials for ZBrush.
In case you missed it, 2 years ago Character Artist Daniel Rigler has released a great ZBrush Matcap Pack that currently contains 204 various materials. The pack is optimized for sculpting and quickly presenting your work. The author promises to keep adding new materials in the future. Anyone who purchases the pack will receive free updates forever.
The pack also has a free demo version that contains fewer materials but is perfect for those who want to try the materials first. The sample collection can be downloaded here.