Here are three substances from most dense to least dense, along with their approximate densities:

1. Osmium: 22.59 g/cm³

2. Iridium: 22.42 g/cm³

3. Platinum: 21.45 g/cm³

These are all precious metals, known for their high density and resistance to corrosion.

Important Note: Density can vary slightly depending on factors like temperature and pressure.