Superman isn't boring at all, I just think its harder to write good stories for him.
Dude is literally an alien posing as a human for part of his life(as Clark Kent). Superman is the most human-like at moments like this(from All Star Superman):
He didn't have to save this chick. This chick was literally a none character, only referenced to earlier in the comic. Her doctor got held up and couldn't be there for her. But in the grand scheme of things she's not important at all and that's how she feels when she's about to jump off this building. But she was important to Superman because he values human life. He can't save everyone but he tries and the thing is he doesn't have to. Why should he care about humans? He's an alien! Think about the fact that this dude could literally kill everyone on Earth easily if he wanted but that's not who he is.
It's moments like this when you see what kind of dude Superman is. He's powerful enough to destroy the entire planet but he chooses to protect the Earth instead. Why? There's no hidden motive. There's nothing in it for him. He's not trying to trick anyone. He does it because he's Superman.
I'm of the belief that there are no boring characters. It's up to the writer(s) to make these characters interesting. Superman in the right hands and written well is a great character and one of the best in comics.