What's there not to?!
I mean, I like a lot of DC characters. I'm even a fanboy of Animal Man, but Clark and Hal and definitely two of the characters I like the most. Constantine too.
I like Clark because of how he's exactly what you wouldn't expect from a man with his powers. As Bruce puts it, he's a boy scout, he never ever abuses his powers despite having the power to easily conquer the world and most of his stories revolve around his personal problems trying to fit in as a human. I also love that he's a reporter: he has the strength and the brains to do any job in the world and have as much money as he would dream of without doing anything illegal, yet he chose to be a reporter for two reasons: because his powers don't help him write better and he likes having to put some effort, and because being a repoter he can keep helping people and society even when he's not Superman.
Hal is a character I've always thought about cosplaying. I love all the human green lanterns, especially Kyle and John Stewart, but Hal is just special to me. I love the theme of the GLs, the whole "in the brightest day...", in the end his toughest battles are just as simple as "be brave and trust yourself". They're characters that can push through anything as long as they do that and I get excited every time he gets a boost of power like that. Hal, most of the time, doesn't seem to have the right attitude to be a hero: he gets competitive (and not always in a healthy way), he sometimes makes fun of people and even be a little bit of a cocky bully, he also had a terrible attitude towards Carol after she broke up with him, which are all negative traits, but when it's time to save someone or do anything heroic he doesn't think of the consequences and rushes in even when he doesn't have his ring, and he does it just because it's the right thing, not to gain anything. So I love him for that.
On the topic of Clark, I'm also a fan of the trope of having evil alternates of him. Since he's such a "good boy" it's very easy to just create an opposite evil alternate. Ultraman, Superboy-Prime, the Homelander, the Plutonian, that mustached guy from Invincible... the kid from Brightburn... I love them all.
The thing about DC is that I dislike many of their stories. I don't like many of their films and also not many of their most recent comics, but I really like their characters and heroes, more than the ones from Marvel (which I also like anyway).