What are the six strongest acids? What are the six strongest bases?
The above are all strong acids or bases in water. They may not be an all-inclusive list or perfectly the strongest, but they should cover what you are most likely to see.
Among the bases: Note that most of the alkaline earth metal hydroxides are left off. Apart from barium hydroxide, they have limited solubility in water, and by that fact they are considered not as strong bases.