Hehehehe, This is what happen when you Vote first and then read the Title thread...I just voted for one Character....
Well, My first choice is L, As Geta pointed out, is not only his Intelligence and Deducting ability, but it his Eccentric behavior, From eating lots of sweet, to his Peculiar way of sitting he is really. He is really one cool character. At first I didnt lik ehim (way back when I read the Manga) but for some reason the anime just make me like him quite better now.
My other choice would had been Ryuk, Because I just found him funny.
Then there is Misa, Her childish behavior, goth clothing style and voice are just..ermmm
Monir,
Kina and
Shay should now what Im talking about
Light is really interesting, and At one point he was my favorite in the series, but that sort of died, and now it shifted to L.