From Bulbapedia, the community-driven Pokémon encyclopedia.
This is a list of Pokémon by effort value yield and base experience. Note that the values listed for base experience are only accurate for Generation V or later games. Base experience values for Generation IV or earlier may be found on the pages of individual Pokémon.
When a Pokémon is defeated in battle, it will give effort values to the Pokémon that participated in the battle against it. The values shown below are the effort points that a Pokémon will give since Generation III, and every four effort points a Pokémon has in a given stat will ultimately translate to an extra point in that stat (before Nature is taken into account) when the Pokémon is at level 100. Prior to Generation III, however, a Pokémon would actually give effort points equivalent to its base stats.
Base experience is a factor in determining how many experience points a fainted Pokémon will give to the Pokémon that defeated it.
List of Pokémon by effort value yield