Of all the characters that tug at the chords of our hearts, my most favorite (and in my opinion poignant) character is Severus Snape. Throughout the Potter Series, the kind of hatred the character evokes in the minds of readers, all and sundry, is of high level. And when the readers realize the sacrifice, the miseries and the yearning for his unrequited love all these years, it is a heart touching scene.
Many similarities exist between the protagonist Potter and Snape, especially, both being orphans and having an unhappy childhood. But I feel that Snape was more miserable because earlier he had thought that once he reached Hogwarts, he would be the happiest man in the magical world and he used to share this feeling with his only friend Lily Evans whom he truly loved.
But upon reaching there, the loss of his only friend and his true love and getting constantly humiliated by a particular group made him feel wretched and isolated. He withdrew into a shell and immersed himself in studies. Being in the Slytherin house, he too became fascinated and involved with the activities of the Dark Lord, creating a permanent rift between Lily and himself.
But, the moment he realized the graveness of his actions which ultimately led to the death of his 'lady love', he felt wretched and the remorse he undergoes is far beyond comprehension. Then his resolve to fight the Dark Lord and to protect the only child of his love is what makes him the bravest man among all the characters in the Potter series. The most touching moment for me was when he realized the futility of all of his selfless sacrifice and actions at his deathbed.
Thus, Snape remains my favorite character in the Potter series.