Ryo Asuka and Akira Fudo from Devilman Crybaby~
To be honest, I had to acclimatize to the style of animation that this series was done in, but by the end, I was hooked. Crazy epic ending * ___ *
I loved how strange and unusual and dark the relationship between these two were. Childhood friends turned enemy is a trope that has been done over and over and over again, but still, Devilman Crybaby brought such an emotionality to their tragic fates at the end that I had to give in to :)
Loved the soundtrack, too! Man!