- Narumi Ayumu from Spiral : the bonds of reasoning ?
- Sou Touma from QED ?
- Hajime Kindaichi from the Kindaichi Case Files ?
- Kyu from Detective School Q ?
I think Narumi Ayumu is the most intelligent character of ALL mangas !
He is very knowledgeable, very far-sighted as if he could read in other persons mind. Unlike Conan, he doesn't solve cases by luck. Futhermore, he can cook and plays very well the piano !

http://www.pika.fr/new/sites/default/files/big_image_8809.jpg