>Shit Tier:
The anime, Generations, the Mangas, and the games must all be canon at the same time.

>Low Tier:
The Anime and the games are canon.

>Mid Tier:
The Games and the Manga are canon.

>High Tier:
The games and Generations are canon.

>Top Tier:
Only the games are canon.

>Delusional Tier:
The in-game pokedex means anything.