The first type of manga I want is with a confident, always cool (even while being thrashed) hero/heroine who actually has a right to be confident, especially the ones that can say lines like, "I'm about to kill him," with a straight face.
The second type is one where the main character becomes scary after they snap. Someone who is normally cool and collected explodes or someone who is normally nice and a pushover cracks (with violence and actual power please).
The third type is someone who enjoys fighting and is strong. They can be slightly crazy, but no psycopathic maniacs (unless they change throughout the series).
Another type I like is the absurdly strong, manipulative, or violent person who hides it beneath a cute facade (no murderers).
I'm being way too picky (Sorry) but I really feel like reading something like this. It can have any of these heroes or someone who is just interesting. These characteristics can be for comic or dramatic effect. Bishounen are appreciated (especially crazy, but not too evil ones).
Some of my favorite manga are Skip Beat, Tokyo Crazy Paradise, Pheromomania Syndrome

(I sound like I'm doing a job search. I apologize for the long description again and any replies are really appreciated.)

http://shoujomaniac.free.fr/forum/?u=75

Akuma to Love Song
Cynical Orange
Mana
1st story in Swan Lake
Kimi wa Petto

and maybe http://www.mangaupdates.com/showtopic.php?tid=3177&hl=emotionless
OR
http://www.mangaupdates.com/showtopic.php?tid=4534&hl=yandere

[url=http:////www.mangaupdates.com/showtopic.php?tid=42718][img]http://i366.photobucket.com/albums/oo105/CatzCradle64/Avis-Sigs/FunghiPower_zps2a00ba56copy_zpsfc03990e.png[/img][/url]

Akumetsu protagonist matches the one you first listed

Sites for reading manga
mangafox.com
mangavolume.com
mangahut.com
onemanga.com
anime-eden.com
manga.bleachexile.com
mirror1.homeunix.com
rootmanga.com
mangarooter.com
groups.msn.com/planetxynx/tod.msnw
thespectrum.net
mangarun.com

Thanks, for everyones help, that should be enough site. 😀 Remember manga is a joy to be shared with everyone.

It's an anime and light novel series, but Kazuma from Kaze no Stigma is exactly what you are looking for. He's always cool and confident and can definitely back that attitude up and then some (he fights a lot of the time with his hands in his pockets).

In episode 20 he snaps and goes on a rampage, while still being totally cool but angry and merciless at the same time

Shin Angyo Onshi
Zetman
Togari
Red Eye
King of Hell
Eatman
Blaster Knuckle
Blade of the Immortal
Berserk
Übel Blatt

SeeYa

Gorath

Thanks a lot; I'll check into those. 😳

http://shoujomaniac.free.fr/forum/?u=75

Gokusen, maybe? For the liking fighting and is strong part.

Does the walker choose the path, or the path the walker?

for the first one, GTO <- onizuka is a champ

ah!
I have one of the tip of my tongue.
I'll get back to you ><

[img]http://i213.photobucket.com/albums/cc143/jjbanaNANA/pichu.gif[/img]
[color=orange]Click the Pokemon.[/color]

Quote from tbl

It's an anime and light novel series, but Kazuma from Kaze no Stigma is exactly what you are looking for. He's always cool and confident and can definitely back that attitude up and then some (he fights a lot of the time with his hands in his pockets).

In episode 20 he snaps and goes on a rampage, while still being totally cool but angry and merciless at the same time

Dont reccomend this actually, besides the main character, it's filled with stupid shonen cliches. The female lead is a tsundere who's personality is EXACTLY like Chidori from FMP. The action sequences are rather interesting, but not OMG blow my mind amazing.