The "What Makes That Guy/Gal so interesting?" Thread

[Kyanbu The Legend]

So while working on story element for my own projects. I was thinking a lot about some of the Shows and Movies I've seen. And the characters those stories focus on and around.

What makes a character interesting? What is it about them that helps draw you into the story? What makes you care about their triumphs and struggles?

For me it's more their interactions with the world around them and how the world reacts to them that makes a character interesting. I've never really found my self being drawn away from or bored of a character solely because of their personality alone. At least that doesn't happen often. There are some rare cases where I can't stand them. Usually only when the "Idiot Hero/Heroine" trope is taken a little too far. For example, Spongebob and Patrick during and after Season 3 of the show.

What about all of you? What do you feel makes a character interesting and why?