We could genetically give ourselves for example:
Greater memory thereby enhancing our own intelligence
Greater Reflexes
Greater Senses, imagine altering our eyes so we can see more than just our current 3 cones of color that defines all we see. This could enable us to see things not even apparent to the "visible light" spectrum we see now.
Eliminate the need for many of the things we require. Such as oxygen tanks in the ocean or most or the equipment we require when exploring space.
Greater Strength
Greater Durability by manipulating our skin, bones, and other tissues to make them more versatile.