Hey!
I'm looking for a manga where main character is "falling to the dark side" because of what happened to him. Something along the story of Kilico:

The main char from cop becomes a hitman for mafia just to get his revenge

Can be also manga where antagonist is presented well enough so you can understand his motives and why did he go to the evil side.
And yeah I did read Berserk. 😀

I can't believe I'm saying this but have you tried Naruto yet?
You have, haven't you?

And;
Vinland Saga
Death Note
Code Breaker
Nabari no Ou (Well, sort of.)
Lost+Brain

Lets see.
Well all of these may not fit your descriptions but they are still "evil"

Shamo (A must read for you)
Riki-Oh
Onani Master Kurosawa (He's wierd, but god it's good)
Death Note
Lost+Brain (He's evil from the start 😛 ))
Code Geass Lelouch

Yes I did try Naruto and thats all I'm going to say about it 🤣
I read Riki-Oh to like chapter 20 or so and then kinda dropped it. Didn't really see him changing from the righteous way into evil one.
I've read Death Note and I've read everything thats been translated from Lost+Brain.
As for CG I'm watching anime. 😛
I will give Shamo a try. Thanks a lot.

Oh yeah, about Shamo.
It has male rape from the beginning but don't let that discourage you to read it.
It's a great manga.

Ares
Vampire Juujikai

They're disputable though. It depends on what you consider evil. But they are both good so you should give them a try.

Also Elfen Lied and Gunslinger Girl are two good choice, I suggest you to try them to see if they are what you want.

If you consider killing (not for self-defense) an evil act all of them are what you're looking for.

What I like in Trivial Pursuit style. Pick your category:[img]http://i379.photobucket.com/albums/oo233/Reid4891/Manga/trivia-1.jpg[/img]

not sure if it will help but vagabond, berserk and ubel blatt have bad ass main characters not exactly evil

black lagoon

"Hip-hop was set out in the dark. They used to do it out in the park"

desert punk for sho!

Quote from veternari

desert punk for sho!

Wasn't he evil since the beginning?

Well actually while I'd prefer to see "fall" of the hero to evil I won't say no to any manga with interesting evil character.
Holyriot I enjoyed Shamo a lot. Im in chapter 170 or something and now it starts to loose its class.

Quote from KennEH!

Quote from veternari

desert punk for sho!

Wasn't he evil since the beginning?

Still... his character is just too awesome to miss.
Such a good anime...makes me wish there was more.

[img]http://img716.imageshack.us/img716/6818/29042893.png[/img]
[img]http://img.userbars.pl/69/13603.gif[/img]

vinland saga
kuroshitsuji
vampire juujikai
akumetsu
death note
hell girl
kaze no stigma - if you can find it
Yumekui Kenbun
alive - but only the first book. its a completely different story
jackals
code geass but i can only recommend the anime (best ever!!!)

Kurohime

It's in the later chapters.
Kinda..?

"I've seen a look in dogs' eyes, a quickly vanishing look of amazed contempt, and I am convinced that basically dogs think humans are nuts." -John Steinbeck

Quote from xtr3m3dude

Quote from KennEH!

Quote from veternari

desert punk for sho!

Wasn't he evil since the beginning?

Still... his character is just too awesome to miss.
Such a good anime...makes me wish there was more.

You could always read the manga. 😛 It was first.