Yuri in Faeries' Landing cuts up Ryang's (the object of her obsession) face for breaking up with her, and she can and will do anything it takes to keep any other girls away from Ryang.
Jae-min in Orange Marmalade follows Ma-ri around a lot at the start and when she accuses him of stalking her he says he's happy when he's watching her. Eventually their relationship becomes more mutual and he stops following her around. Later, when Si-Hoo is introduced, he begins stalking and harassing Jae-Min.
The Barenaked Ladies give us "Straw Hat and Old Dirty Hank", based on the Real Life stalking of singer Anne Murray (and referencing a number of her songs in the process).
Played with in Whodunnit?, as Bruno is this for Trixie; he keeps a locker full of her pictures and news clippings. Justified in that he's actually her father, Tex, who came back from the dead and is out to protect her.
The first case on the Sick Sad World episode "Mysterious and Unsolved Cases" features one of these. When said stalker's target is kidnapped and murdered, he takes up calling her mother and saying "I've got her" or "I killed her". Mari and Jasmine speculate he wasn't the killer. Instead, he kept calling because he wanted the target of his obsession found and to continue having power related to her by harassing her mom.