Weird... I can not find them all anymore...
Maybe they were removed or something...
BUT lets go with what I could find...
MECHA WEEK!!!
1: Break Blade -
http://mangafox.me/manga/break_blade/Site Blurb -
From Manga Abyss:
Which to choose, the country or my friend--!? The "Continent of Cruzon", a world where people are born with magic. Lygatto, one of the rare people "without magic" in this world, is getting swallowed up in the whirlpool of a massive war. With Lygatto as the core, four close friends are connected by cruel fate in a spectacular war tale!!!
In the continent of Cruzon, an impending war between the Kingdom of Krishna and the nation of Athens is brimming. The people of this land are able to wield the crystals from the ground for whatever purpose they desire. Yet one person, Lygatto Arrow, is not. He is an "un-sorcerer", a person unable to wield the crystals. But this characteristic will enable him to pilot an ancient mecha, one strong enough to put up a fight against the invading army of Athens.
Summary by solitaryCross
From Baka-Updates:
Rygart Arrow is the only one in his world who lacks the inherent ability to power up quartz, the energy source that makes all of the machines run. Nevertheless, he's pretty well connected. The King and Queen of his country of Krisna happen to be old college friends. But so is Zess, the guy who is leading the army of a neighboring kingdom in an attack on Krisna.
How did it comes to this? There's little time to ponder the implications as an army in giant, mechanized battle suits attacks. Arrow just feels like he's in the way - until he comes across a powerful, ancient mech that no one has yet to be able to figure out how to run. But his natural affinity for the suit's operating mechanism may just turn Arrow into the most important player of all.
Personal Blurb -
I found this when it first came out, annoyingly the gaps between releases made it a slow slow slow read thus I lost it for a while, but it looks like the releases are picking up again to a point, so might get back to reading this one though.
This Manga is about a world where every citizen has the ability to perform what appears to be Magic though the medium of Quartz Crystals. Well all but the Main character, in this world sometimes a child is born without the ability to manipulate these magics and thus struggle to form any true lifestyle due to the citizens of the world basing nearly everything on these Quartz Mediums. Even lights are used this way. But dispite that he struggled through, even got into a high ranking school of sorts making friends with those that many would think would be way out of his league, regardless times change...
Two Nations both at war use Mecha to fight, powered by the Quartz Powersources they combat and such. But then one of the nations discover an old Mech buried below their land, a mech that is not powered by Quartz and thus inoperable. Well.... Sorta...
2: Eureka Seven -
http://mangafox.me/manga/eureka_seven/Site Blurb -
From Mobots:
Renton is a 14-year-old boy who occasionally helps out his grandfather as a mechanic. But his feelings of dissatisfaction and frustration grows as his mundane and routine work clouds his visions for his future and he dreams of flying around the world. It isn't until one day, a large human-like mech, a LFO (Light Finding Operation), falls from the sky in front of Renton and appearing from the depths of the machine is a beautiful young girl named Eureka. And as she asks the dumbfounded Renton for repairs, the two will embark upon a fantastic journey into the unknown.
Personal Blurb -
If you haven't heard of Eureka Seven before, go read this or watch the anime, its good...
3: Overman King Gainer -
http://mangafox.me/manga/overman_king_gainer/Site Blurb -
In the distant future, in a distant corner of Siberia, people live in domed cities called Domepolises. These are the primary human living spaces on Earth, which became uninhabitable years ago from environmental destruction. Now, parts of the Earth are becoming habitable again. Large portions of the Domepolises are breaking off to escape the powers that control the domes and trade.
Gainer Sanga, video game champ on his 200th victory, becomes an unwilling helper in his hometown`s Exodus when he is wrongfully arrested by the Siberian Railway. He pilots a giant mecha which he dubs `King Gainer` after his own video game handle. He is challenged to fight other Overmen as Yapan tries to escape across Siberia.
Personal Blurb -
I found this one ages ago, once again the Updates stopped coming for a really long time, thus I pretty much forgot about it, another one which I will be picking back up laters. Sadly I can't not remember much of the actual story to give a good blurb, BUT, I know that it had beautiful artwork and designs for the Mecha and world itself...
4: Annoyingly, Missing or I just can't remember the title... T_T But there is just TOO MANY GUNADUM!!!