Another idea for a 'Harry Saves Vernon' fanfic could be set during a time when the wizarding world is under attack and the protection spells around the Dursleys' house fail. Harry, who has a sense of duty towards his aunt and uncle despite their past treatment of him, comes back to save Vernon from the invading dark forces. He might use his Patronus charm to drive away Dementors or use defensive spells to fend off Death Eaters who are targeting the Muggles in Little Whinging.
Another one could be 'When Draco Saved Harry'. It might show a scenario where Draco saves Harry from a cursed object in Hogwarts. This fanfic could explore how the other students react to this unexpected turn of events, and how Draco and Harry start to see each other in a different light.
One popular 'Harry Saves Ginny' fanfic might be 'The Rescue of Ginny'. In this fanfic, Harry uses his quick thinking and powerful magic to save Ginny from a dangerous dark wizard. Another could be 'Harry's Heroic Save', where he overcomes many obstacles to reach Ginny in time. There are also fanfics where Harry saves Ginny from a magical creature gone wild, like 'Saving Ginny from the Basilisk's Lair' which has an exciting plot full of action and adventure.
There could be a 'Harry Saves Daphne' fanfic where Harry saves Daphne from a group of dark wizards. This event changes Daphne's view of Harry completely, and she starts to see him in a new light, perhaps even developing feelings for him. The story then follows their adventures together as they face new threats in the wizarding world.
One great 'Harry Saves Hermione' fanfic could be 'The Rescue in the Forbidden Forest'. In this fic, Harry uses his advanced magic skills to fend off a horde of dark creatures that are about to attack Hermione. Another might be 'Saving Hermione from the Time Trap', where Harry travels through time to rescue Hermione from a dangerous situation she's stuck in. And then there's 'Harry's Heroic Moment for Hermione' which focuses on the emotional bond between them during the rescue.
There's also a fanfic where Ron saves Harry during a Quidditch match gone wrong. Harry's broom is jinxed, and Ron, with his knowledge of broom mechanics and some quick spell - casting, manages to break the jinx and catch Harry before he falls. It shows Ron's loyalty and his ability to act under pressure.
One great 'Hermione Saves Harry' fanfic is 'The Saving Grace' where Hermione uses her quick thinking and powerful magic to rescue Harry from a dangerous dark wizard's trap. The author does an amazing job of portraying Hermione's intelligence and determination in this fic.
One great 'Harry Potter Saves Hermione' fanfic could be 'The Rescue in the Forbidden Forest'. In this fic, Harry uses his advanced magic skills he's secretly been practicing to fend off dark creatures that are attacking Hermione. Another one might be 'Harry's Swift Intervention', where he arrives just in the nick of time to save Hermione from a dangerous spell gone wrong during a duel. And there's also 'Saving Hermione from the Abyss', which has a really intense plot where Harry has to brave many obstacles to reach Hermione who is trapped in a magically created abyss.
One great Vernon Dursley fanfic is 'The Unseen Side of Vernon'. It delves into his character in a unique way, showing his insecurities and how his upbringing might have shaped his rather unpleasant personality towards Harry. Another one could be 'Vernon's Redemption Arc' which is an interesting take on him trying to make amends for his past behavior towards Harry.
Dudley might face his father's anger. Vernon could be furious that Dudley has gone against him to protect Harry.
Perhaps Dudley finally stands up to his father's cruel treatment of Harry. Maybe he realizes that Vernon's behavior towards Harry is wrong and uses his own physical strength or some clever ruse to get Harry out of a difficult situation Vernon has put him in.