Its very common, and very cliche.

But what I'm looking for is more of a background type.

I'm looking for a manga where the main character is already Powerful, Amazing, and intelligent. Also the manga can be where the character is smart, but gains a new power and uses it. (sort of dragon ball zish) Can be Romance, Tragedy, Shounen, Adventure, anything at the most.

Except
I'm not looking for any shojo, yaoi, yuri, hentai manga. Also I disike rape, by what any means.

I'm looking for a character whose personality is not that of a stupid idiot like of most shounen romance manga, where they can't decide.

Main Character prime examples would be:

Death Note (very intelligent, and cool)
Hellsing (very cocky, but has the bite to back it up)
Bleach (he's not directly an idiot, he's strong, not stupid)
Yougen No Chi (he is powerful all together, with a normal obsolete attitude)
Ubel Blatt (just cool)

Is actually all I can think of.

Idiotic Character by my means

Naruto (for some reason, I find him annoying)
Suzuka (comparatively he gains "power" but just pointless idiotic choices)

Those are actually the list of manga I can actually only think of to help you give me recommendations. Genre search for shounen/sienen would only lead me to a endless clicking spree for hours.

Code Geass, very similar to Death Note in the main character.

Aflame Inferno - You could almost described the plot of this one with the whole smart strong dude gains powers part
Id recommend more, but the whole concept of "strong from the get go" is very vague and the list would be pointlessly long and unhelpful I'm guessing

Double dino to micro crimp!!!

Berserk- Possibly featuring the most Badass character of all time
Blame-Moderately powerful main character with a cool attitude
Dogs-One of the main characters matches the specifications
Jackals
Kurosagi the black swindler
Eternal Sabbath
Jack Frost-Kind of similar to Hellsing
Spiral-maybe

Akumetsu <==exactly what you're looking for, though he's not a genius he's really into economics.
Lost+Brain <== reminds me alot like Death Note
Kurosagi Corpse Delivery Service <== main character very cool and usually stays calm even in the most bizarre situations.

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How about Eden. Main character goes from pussy whipped spunk wiper to badass killer.

Sarcasm just doesn't work over the internet.

Quote from DeathDealer88

Blame-Moderately powerful main character with a cool attitude

Main character's strength is primarily due to the uber-powerful weapon he is in possession of, not exactly attributed to the main character himself.

You've probably read them since they're pretty popular, but I'll recommend Rurouni Kenshin and Trigun to be on the safe side.

Jiraishin has the genius badass theme, though it is pretty realistic.

"When we remember we are all mad, the mysteries disappear and life stands explained."

• Samuel Clemens/Mark Twain

How about Eatman

[img]http://i61.photobucket.com/albums/h46/lh_4ever/n79231101368_2219924_5452403.jpg[/img]
Slow internet is DEADLY

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hmmm..............try Kurohime or Shina Dark

I can't suggest enough Spiral, I know that I'm pratically suggesting it in every topic, but it really fits the description, the main character is a genius. It's a detective/mistery story, so if you don't mind the genre, you should try it.

Other manga where the main char is outstanding imho:

Shin Angyo Onshi -> probably what you're looking for. Main char is determined and a little cynical and there is a curse that restrains him.
Vampire Juujikai -> another great main char.
Ares -> well, simply the best shounen manhwa ever.
Kurogane -> cool
Kurozuka -> cool
GTO -> coolest teacher ever.
ES -> cool

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

Parasyte - From the second volume, after a character change.
Gantz - It takes a while, but the main character develops from an emo looser, to a leader that is admired.
Code Breaker
Team Medical Dragon - The main character is more or less the Japanese version of Dr. House.
Sanctuary - Hojo and Asami are men amongst men.

i second GTO

also i didnt and dont like these 2 mangas but u might... Ichi the Killer and Shamo

The Don: Young Makaveli

love is evil, spell it backwards and I'll show you...

"my mind shines bright even when my thoughts seem dark"

Never Ignorant Getting Goals Accomplished

The Hate U Give Little Infates F***s Everybody

justILLMATIC

Hunter x Hunter is similar i guess

Mx0 if you haven't read it.

I'd second Shina Dark and GTO, but only to an extent.

[img]http://www.joeshen.thewafflehouse.net/web/Setsuna_Small.jpg[/img]
真実はいつもひとつ. ~ "There is always only one truth."

Rurouni Kenshin
^Read it, love it.
Trinity Blood
Immortal Rain<<Idk bout this one
Tsukihime
Air Gear
Tenjou Tenge
Actually, your requirements are pretty much all shounen manga >.>

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What a tangled web we weave, when we practice to deceive
:=EXITUS ACTA PROBAT=: