Source: nerdist.com

5. Iron Man (Tony Stark)

Yes, yes, of course. Tony Stark, aka Iron Man, is one of the smartest people in comic books.

Born to a SHIELD Agent and a HYDRA double agent, Tony Stark was abandoned, only to be adopted by rich industrialist Howard Stark and his wife Maria. His newborn brother Arno suffered from a fatal illness brought on by Howard’s attempt to prevent an alien robot known as X51 from turning him into a bio-weapon, so Tony grew up as an only child. Look, recent writers really liked to tell supercomplicated stories about Tony Stark's birth, okay? It's a lot of retconning.

Anyhoo, Tony would eventually take over his father's company and become a preening egotistical jerkface, a trait that would make him infamous. Eventually, he was blown up in Korea/Vietnam/Afghanistan/Jesus Christ, pick a country, and went on to become the Iron Man.

His brilliance and tech genius would make him the Marvel Universe's resident smart guy who isn't also busy all the time with his family.