L. not just because he's crazy intelligent, but also because of his personality, eccentricity, and ability to eat so many sweets and develop health issues. so the last reason is mostly a joke...but i wish i could do that...lol. when i started watching the DN anime i got all excited cause i sit in somewhat unusual positions, prefer being barefoot, put my thumb to my mouth when i'm thinking, love sweets and coffee, and i even scratch my ankles using my jeans the same way L does. (i admit the ankle scratching thing isn't that unusual, and that i don't put my thumb to my mouth the exact same way L does.) i'm not claiming i'm the female version of L or exact likeness of him. just that we're similar in a lot of aspects, even personality and views. that's why i like L the most - i agree with him entirely.
though Light does make the perfect villian...and i love Ryuk.