For most interesting... Probably have to be Tsukasa from .hack or Misaki from Another.

probably Ace D. Roger, or Gin, or Watase Sanetoshi, or Shizuo... this is pointless~

Well, Narita always does write good characters.

I really enjoy characters with very human traits, so I'll start with Lal'C from Diebuster. She has her own issues, but they don't come off as whiny coughshinji and rentoncough, she has opinions, she makes a great major character. She really made the series great.

After that, I'll go with Kitamura from ToraDora! He's a loyal friend, has his own convictions, and shows a lot of emotion considering his role. He is part of the main 5 characters, but he effects the series in a very serious way and isn't just another chorus character.

Then my other favorite is Watanuki from xxxHolic. I read through this manga almost solely because of the main character. The series isn't fantastic, but I love his motivations and behaviors. Too often we see the same main character archetype. However, watching Watanuki is like watching the main characters friend, thrust into the main character position. He's not confident, nor does he have a handle on most of his situations (before the time skip). After the time skip, his character changes greatly showing that he's also dynamic.

Keima Katsuragi, for me.

edit: (Yes, I know the difference between "favorite character" and "most interesting character")

Feels like making a Claire fanclub now because yolo.

Johan Liebert

Because he terrifies me but I can't stop being intrigued

@Arachne Oh how could I forget Johan, most likely the most twisted soul ever imagined and he's just so damn charismatic.

Shura Kirigakure from Ao no Exorcist

She's badass, sometimes without even trying, can outsmart both Mephisto and Amaimon, has 4 exorcist titles, Takes on Arthur McDouchebag without much thought, etc.

Not much is known about her past though, and I keep on wondering if she's somehow half demon. She has unnatural natural hair after all.

Himari from Mawaru Penguindrum

There are all sorts of speical characters, looking at you Ringo, but I choose Himari. She doesn't seem like it at first, but she has layers, and layers of... angst, drama? I don't even know how to fully describe Himari's character, she's in many ways a conflicted and troubled heroine(?!) for a series.

That's obviously one of Ikuhara's strong points, making good conflicted characters.

Cirno from Touhou

She's the strongest bitch!

Utena Tenjou from Revolutionary Girl Utena

The most classic of tomboys in a anime series, Utena gives the new meaning of innocence I think.

What's odd is that Utena's likely the most sane character within Utena. She remains stable even though the hardest things that would drive a person crazy over time. Except the final episodes... even then she gets back up on her feet to save Anthy.

She's likely the badass of all badass magical girls.

Rin Okumura from Ao no Exorcist

Rin likely puts a new face on 'most screwed character in the world'. Not only is the Order after his guts, but so is Satan, Mephisto (maybe) is using him to kill Satan then take over the throne, plus other things.

He rely's on the power of friendship, yeah, but his friends are really the only things supporting him at this point. That's just incredibly sad, to me anyway.

the most interesting would be

... Zatch bell

DUH! L from Death Note.

Natsuru Seno from Kampfer "A guy that can change into a girl" That's really complicated when ya look smexy as a girl. A new meaning to "A Guy Trapped in A Girls body"

@DarkChaplain

@Inasda if you want boy, girl change over then watch Kasimasi

@DarkChaplain

Does it help if I made the GIF?

lol

Most interesting? I'd have to say Ochibana Ame from Denpa teki na Kanojo.

That girl was full of interesting

@Arachne DAMN. You beat me to it. And that artist was he reason I began MONSTER.

Re-l and Vincent from Ergo Proxy HAVE to be on the list:

http://i41.tinypic.com/zso1oj.jpg

I know he's the least.