HMMMM...
I can't pick favourites, but here are a few I remember well, for various reasons 
Nominated for... Most emotional impact!
And for potentially traumatising a few kids growing up...
Summary
Flukta frå dyreskogen! ("The Animals of Farthing Wood")
For me it has to be in Norwegian, and Nynorsk specifically. I still feel a strong mix of emotions when I hear the intro.
My heart...
Nominated for... Most MAGICAL TRANSFORMATIONS.
And for appealing to my "ooo shiny" magpie soul.
Summary
Tenko and the Guardians of the Magic!
I even used those tricks they taught in each episode, eternally COUNFOUNDING my friends with my MAGICAL power. I still know (and use) some of them. 
Nominated for... moral in every episode.
And for some of the most mood setting music ever.
Summary
Pokémon!
Charmander being left on that rock still breaks my heart...
And Pikachu's farewell will still make me cry, not gonna lie...
Pikachu not evolving to beat Raichu...
Etc, etc, etc...
Nominated forrr... inspiring too much fanfic reading?
And subsequently showing me how anything that doesn't exist in canon, most likely exists in fanon somewhere... Man. I dived way too deep.
Summary
Digimon!
Not even going to go into detail.
People who have gone deep into fandoms before... they know, haha.
I need to rewatch the first season for nostalgia. 
Listening to the intro theme was a blessed mistake.
