The substances that have a pH of 14 are
Lithium hydroxide (LiOH),
Sodium hydroxide (NaOH),
Potassium hydroxide (KOH),
Rubidium hydroxide (RbOH),
Cesium hydroxide (CsOH),
Calcium hydroxide,
Strontium hydroxide,
Barium hydroxide,
Tetramethylammonium hydroxide,
and Guanidine.
There are few superbases such as Butyl lithium, Lithium diisopropylamide, Lithium diethylamide, Sodium amide, and Sodium hydride which are even stronger bases.
The common examples of substances with pH 14 around us are liquid drain cleaner, caustic soda, and lye hair relaxers.