In my opinion, this anime scene is by far the most romantic. I will say this though: the following pictures above and text below will have spoilers for the anime Wolf's Rain.
For wolves disguised as humans, everything is out of the ordinairy. When the band of friends follow their leader Kiba in order to find Paradise, they clash into a battle against Darcia, the antagonist of the story. They soon learn that Darcia himself had discovered the secret to becoming a wolf. They realize they have to take him down, one last time, permanently. However, while pursuing him, many of the characters were severely injured while barely leaving a scratch on Darcia. Blue, half wolf - half dog, especially took a toll on her body and could barely move. Hige as well was just barely clinging on to life. With their end slowly creeping up on them, Blue and Hige use the remains of their strength to be with one another. Blue dies in her lovers arms and Hige comforts her as she slips away. At the same time, Blue herself was trying to make Hige feel prepared, having her with him. She crawled her way to him, regardless of the blood being spilt and regardless of the pain. This is my opinion, but I strongly believe that this is the most romantic scene in anime. After all, what could show more of a love devotion than one willing to die in your arms or one choosing to softly hold you while you pass on together, risking any chance they may have left for life?