1. Water (H₂O): Water is the classic example of a polar molecule. The oxygen atom is more electronegative than the hydrogen atoms, meaning it attracts electrons more strongly. This creates a partial negative charge on the oxygen and partial positive charges on the hydrogens. This uneven distribution of charge makes the molecule polar.

2. Ammonia (NH₃): Similar to water, nitrogen in ammonia is more electronegative than hydrogen. This creates a partial negative charge on the nitrogen and partial positive charges on the hydrogens. The shape of the ammonia molecule, with its lone pair of electrons, also contributes to its polar nature.

3. Hydrogen chloride (HCl): In HCl, chlorine is much more electronegative than hydrogen. This results in a strong partial negative charge on chlorine and a strong partial positive charge on hydrogen. This significant difference in electronegativity makes HCl a very polar molecule.

Important Note: Polarity arises from the uneven distribution of electrons within a molecule, typically due to differences in electronegativity between atoms. The shape of the molecule also plays a significant role.