The character development. Chuck Dixon is great at making Nightwing a complex and relatable character. We see his growth from being Batman's sidekick to becoming his own hero in Blüdhaven.
Well, 'Nightwing: The Great Leap' is also a notable one. In this graphic novel, Nightwing faces some tough challenges in Blüdhaven and we get to see his character develop further. Chuck Dixon does an amazing job with the story and the art in this one is quite good too. It's a great read for any Nightwing fan.
Some of the great ones could be his action - packed adventure stories. For example, if he has stories with heroic characters in challenging situations, those are often really engaging.
One way is to really engage with the themes. Try to understand what Chuck Dixon is trying to convey through his stories. Also, make connections between different stories in the collection if possible. Another important thing is to take your time. Don't rush through the stories. Absorb the atmosphere and the emotions that Dixon is creating. You can also discuss the stories with others who have read them to gain different perspectives.
One possible fanfic could involve a battle against a powerful villain. Nightwing might get injured while trying to protect Gotham. Batman then has to step in not only to defeat the villain but also to take care of Nightwing. He could use his advanced medical knowledge and resources in the Batcave to nurse Nightwing back to health.
One common theme could be loyalty. Given the nature of Daryl Dixon's character in the original show, loyalty to friends or comrades like Gene Dixon and within the context of Trinity might be a big part of the fan fictions.