[DC/Marvel/Comics in General] Are there any good-guys/heroes whose "power" or skill set is pure intellect?

Basically I'm looking for the good-guy version of Lex Luthor. Reed Richards comes close, but he has actual super powers as well (even if they pale in importance next to his mind). Tony Stark is also close, but I'm looking for someone who didn't just turn their intellect into one specific focus that just replicates super powers. You see this a lot in bad guys - Luthor, Doom, etc. - but I can't think of any good guys off the top of my head that fit the bill. Any thoughts?