Iron man (Who could have guessed? :lol) I have a background in mechanical engineering and it's the first superhero I came to contact with (The shitty 90s animated series unfortunately, but I was a kid so I lived it) That is if we're talking Marvel. From DC it's definitely Batman. Similar to Stark, I like the fact that through ingenuity and persistence the normal humans can match and beat superhumans of various kind.