So... Nightwing is an awesome character. There's a lot to be said about this guy that isn't said or noticed by even the most hardcore Batman fans (of which I'm not). I'm IndieKid, and here is why Nightwing is such an amazing character...
Dick Grayson is the very first superhero sidekick, and the very first Robin. Though he famously became Nightwing later on in the comics, I think it's important to look at why the idea of Robin works so well. But specifically Dick Grayson as Robin.
Everything we know about Batman can be summed up with gadgets, fighting skills, crimefighting, wealth, and a dark and traumatic past. You take this great character, and then give him someone to take under his wing (or his Knight-Wing *sorry I couldn't resist), and you instantly have a great idea for a character. This is where Dick Grayson comes in.
Dick Grayson is everything I just described Batman as, but subtracted. His parents were killed like Batman's, he lives in Gotham like Batman, but he doesn't have the wealth or the brooding attitude. So you get a younger Bruce Wayne who isn't rich and has an upbeat attitude, and give him a father-son relationship with Bruce Wayne. Out of that, you get to see them bounce off of each other, bond, and sometimes disagree, as Dick Grayson does (due to Batman's bullshit and deceit).
...But what if I told you this kid became his own superhero?
Then, you get this already interesting character, and put him in a new world, without Batman's supervision, and his own set of problems. We get to see how this slightly altered version of Batman works by himself, and handles his own responsibilities. This makes Nightwing an amazing character.
NEXT - PART III: BATGIRL