I'm really picky about the artwork when I read manga, and I really like this particular kind of style... cuz I think it looks really cute and cool! But it's pretty had to search for mangas according to art style, so I was hoping for some help. The storyline doesn't really matter...
Erm, it's really hard to describe art, so I'll just list some examples of mangas I love.

1. 07-Ghost
2. Harlem Beat Wa Yoake Made
3. Nabari no Oh
4. Amatsuki
5. Persona 3

Considering I only read 07-ghost, I'd say Chrno Crusade (probably World Embryo-same mangaka), D.Grayman )but your avvy says you already read it 😛 ), Crescent Moon (not too sure but w/e), Spiral, Sorayume no Uta, Hyakuman Tsubu no Namida (last 2 are by the same mangaka) and let's say Crimson Cross (because the main character looks like a grown-up Allen 😀 )

Most of them might not have similar art, but I guess you like the 2000'ish style with sharp inking and toning, straight-ish hair and neither too shoujo-ish nor too shounen-ish...I guess...(based on 07-ghost only again)

Ooh yes Spiral is awesome.
Kagerou Nostalgia has it's similarities to 07-ghost and I LOVE both of them.
The art of Nabiri reminds me of Matantei Loki Ragnarok.

Sorry posted in the wrong one but...

Psycho busters seem viable and Shana oh Yoshitsune might be what you're looking for...

Oh yes, maybe Shina dark too...

Edit:

Joshikousei seems like what you're looking for also. Though the scans aren't the greatest but it's readable.

I read Kagerou Nostalgia... it was good but more cuz of the story line than the art, haha, but thxx anyways.
I've already read Spiral and D.gray-man too 🙂 ---> I have allen as my avatar!
I'll give a shot at the rest, thx!! 😀

Senki Senki Momotama and Peacemaker ! I think they have really nice art that fits your description ^^

The later volumes of Kateikyoushi Hitman Reborn! seems to evolve to this type of art too. I love it!

Deadman Wonderland and Doubt (TONOGAI Yoshiki) are great choices too!. 🙂

EDIT: Forgot to say, I personally favor this type of art the most too! x3