This one is very easy: Thomas "Tuds" Tudbury from the Wild Cards series, a.k.a. "The Great and Powerful Turtle." The Turtle is a shy, nerdy boy who can only use his Ace powers while ensconced in a shell that armors him and allows him to view the world through cameras. His confidence falters when face-to-face with people, when he cannot seal himself away. When I read this story I was at a low point in my life: jobless, living with my parents in a crumbling inn in New England, dealing with a nervous breakdown, and completely thwarted by life. I immediately identified with the Turtle in a way that has not happened since.
The Turtle is the superhero I had always wanted to be, and given his personality, I could see myself being a hero. I was desperately looking for something to relate to, and the Turtle gave me an idea of a person that did that for me. I was so much like him, requiring thick layers of protection to do anything significant or creative, always undermining myself, and always stumbling towards the future. That such a character could do that gave me hope. It took me some time to act on that hope, but certainly the seed was planted in my mind through the adventures of the character.