I tend to regard all the different generations as being one giant anime, rather than separate entities in a specific region. Aside from the long-running anime, which may or may not include Pokémon Chronicles (episodes focusing on other characters), there are 20 full-length movies, plus a handful of smaller series like Generations, Origins, Raikou, and I think a mystery dungeon series as well, that pay tribute to the games. Pretty sure there are a few spin-off episodes on top of that.