L Lawliet
L Lawliet, exclusively known by the mononym L, is a fictional character in the manga series Death Note, created by Tsugumi Ohba and Takeshi Obata . While he was beaten by Light, he almost succeeded without knowledge about the Death Note for quite some time. He nearly solved the case without any help from the supernatural at all.
He would have solved the Kira case if it wasn't for Rem's sacrifice. So technically, L won... in a way.
Light was smart, but he made dumb mistakes. L is more clever.
Light Yagami
Light Yagami is a fictional character and the protagonist of the manga series Death Note, created by Tsugumi Ohba and Takeshi Obata. Light was able to outsmart L, even when he was in a hopeless situation. Even when they were working together, Light came up with solutions quicker than L more than once. They're both smart, but I believe Light is smarter. The only reason people deny it is because they personally prefer L as a character.
Light is better than L and Near, both!
Light beat L, so he's smarter.
Near
Nate River, exclusively known by the mononym Near, is a fictional character in the manga series Death Note, created by Tsugumi Ohba and Takeshi Obata.
Naomi Misora
Naomi Misora is a fictional character in the manga series Death Note, created by Tsugumi Ohba and Takeshi Obata.
Mello
Mihael Keehl, universally referred to by the mononym Mello, is a fictional character in the manga series Death Note, created by Tsugumi Ohba and Takeshi Obata. He was the one who basically beat Light in the end. Near's plan would have failed pathetically if it wasn't for Mello and his sacrifice.
Watari
Matt
It was reported that his calm demeanor and laid-back attitude were the reasons why he is third in line to be L. His lack of motivation and drive are the only things holding him back from being first. His intelligence even surpasses that of Mello and Near.
Goddamnit, Matt... you cinnamon roll...
Teru Mikami
Kiyomi Takada
Kiyomi Takada is a fictional character in the manga series Death Note, created by Tsugumi Ohba and Takeshi Obata.
Halle Lidner
The Newcomers
? Teru Mikami
Teru Mikami is a fictional character in the manga series Death Note, created by Tsugumi Ohba and Takeshi Obata.
? Ryuk
Ryuk is a fictional character in the manga series Death Note, created by Tsugumi Ohba and Takeshi Obata.
The Contenders
Roger Ruvie
Stephen Gevanni
Touta Matsuda
Touta Matsuda is a fictional character in the manga series Death Note, created by Tsugumi Ohba and Takeshi Obata.
Anthony Rester
Soichiro Yagami
Hideki Ide
Shuichi Aizawa
Kanzo Mogi
Misa Amane
Misa Amane is a fictional character in the manga series Death Note, created by Tsugumi Ohba and Takeshi Obata.