Gwen Stacy

Peter Parker met her in college where his preoccupied life as Spider-Man made him seem aloof. Eventually, Gwen warmed up to him and a romance developed. That became more complicated when her father, Police Captain Stacy, was killed in a battle which involved Spider-Man and Doctor Octopus. Gwen blamed Spider-Man for that and so it hung like a Sword of Damocles, but unlike before with Betty Brant, Peter was ready to deal with it.

Eventually, she was murdered by the Green Goblin at the George Washington Bridge despite Spider-Man's attempt to save her. A clone of her was developed by an insane professor, but eventually that character established her own identity.