Here are a Few of my top.
I will start with Sundome("suhn-doh-may") literally meaning "stopping the moment before," and considering the content of the story, it refers to being stopped just before coming or ejaculating. Which really sucks and can be very painful.
Besides the summary of the story (From Yen Press:
The “Roman Club,” a school group interested in the occult, to which he’s practically enslaved, has become boring for one Hideo Aiba. Until a girl named Kurumi Sahana shows up and wants to join up. But Sahana is no ordinary girl… When the two are left alone in the club classroom, Kurumi makes a special “request” of Hideo… From that moment on, Hideo’s dull life gets far more…frustrating.) I don't want to add any spoilers but i must say for those who are 18+ this is an excellent manga to read and i would highly recommend it, for some one who is in to the d/s side of sex even those who are it will give a new incite into the emotions and pains people go threw.
Next is Gantz (ガンツ Gantsu) "Your lives have ended. What you do with your new lives is entirely up to me. That's the theory, anyway." This ominous green text appears on a black sphere in an unfurnished Tokyo condominium from which the Tokyo tower may be seen. A pair of high school students, Kei Kurono and Kato Masaru, are seemingly run over by a subway train, after saving the life of a homeless drunk who had fallen onto the tracks. Following their untimely deaths, Kei and Kato find themselves transported—alive and well—along with a number of people who have also just died, to this condominium.
That's enough of the summary its rather lengthy, what ill say about Gantz well hmm lotz of violence, blood gore, sword play and futuristic weapons. If you are the type to get mentaly into what you are reading be ready to feel pain, anguish and happness. (Lol same can be said for most of the great manga) a well developed story that dosent tapper off in the end, so far as there has been still hoping for more to come.
Onto I"s (アイズ Aizu)(Not to be confused with IS) is a japanese teenage romance manga by Masakazu Katsura. This is by far one of the best manga i have read to date. The story's main character is 16-year-old high school student Ichitaka Seto who is in love with his classmate Iori Yoshizuki, but too shy to tell her. Again and again he plans to tell her his true feelings, but each time something (usually a misunderstanding of some kind) gets in the way. Things become even more complicated when Itsuki Akiba, a girl Ichitaka was friends with in their childhood before she moved to the United States and who had a huge crush on him, returns to Japan. The story line is never dull and consantly is heaping emotions onto loads of happness and joy, but still hitting home with emotional sadness. I had no trouble relating to the main charater and if you like my you start to feel the emotions he is having. I must admitt at time these emotions where to the point i couldnt bear to read more but craved it at the same time. I recommend this to any one who truely loves to read manga. Not for the faint of heart(if you get deeply attached to the story that is.)
Next on my top list is Magical Teacher Negima! (魔法 先生 ネギま! Mahō Sensei Negima!) After graduated from a magic academy, 10-year-old genius boy Negi Springfield was assigned to a huge Japanese school as an English teacher for practical training. To his surprise, the 8th grade class assigned for him is all-girl. In addition to teaching (and being teased by) those 31 pretty girls while trying to keep his magic capability in secret, he's also looking for clues about his father, who was once known as "Thousands Master" but mysteriously disappeared years ago.
I Know this is a bit off the the previous manga but i like the story line, what can i say i have wierd taste idk. so far this manga has yet to disapoint as with most i find that the end of the chapter comes way to fast but same can be said for any manga that leaves you craving for more. there isnt much i can say tho estounding drawing, the story progression is exelent and the charater detail is such that it gives you a great insite into them selfs.
1/2 Ouji aka:half prince It is the year 2100A.D., humans have developed a virtual reality game. Feng lan, due to a bet with her brother, vows to beat the game without using her "female benefits". Due to this, she becomes the first transvestite of "Second Life".
Bloody Monday A virus deal clinched in Russia on the Christmas eve. Purpose: unknown. Two clues: a mysterious lady "Maya", one of the gangsters, and "Bloody Monday", the keyword for the project.
Then an incident happened in far-distant city of Tokyo. Fujimaru Takagi, a second grade student at Mishiro Gakuin high school, is commissioned to find out the truth by the Public Security Intelligence Agency, for his great ability as a super hacker. Now, Maya approaching to Fujimaru as his high school teacher...
Gekkoh Kyotaro is just an ordinary guy trying to lead an ordinary high school life despite the fact that he is the son of a Yakuza boss. Then comes Kumiko, his half-sister he's never met before, who's looking for a man with a centipede tattoo who killed her loved ones in the past. Will Kumiko and Kyotaro be able to manage their family business? Will Kumiko ever find and avenge the man with the centipede tattoo? And will they be able to control their sexual urges for each other?
The Melancholy of Haruhi Suzumiya On the first day of high school, Haruhi Suzumiya make an announcement that stunned everyone: "I don't have any interest in ordinary people. If anyone here is an alien, time traveler, slider, or esper, please, come see me! That is all." Kyon, a totally normal human who happens to have the misfortune of sitting at the desk in front of Haruhi's, wondered at first if she was joking. But Haruhi Suzumiya is always serious. Always. In any case, Kyon certainly never intended to get involved in her antics. But when a casual conversation accidentally gives Haruhi the idea to form a club dedicated to the discovery and investigation mysterious phenomena, Kyon finds himself already in over is head, especially when Haruhi makes him her first recruit. Other members of the club include Nagato Yuki, a quiet, bookish girl; Mikuru Asahina, an all-too adorable girl chosen by Haruhi to be the club's "mascot"; and Koizumi Itsuki, an always-smiling boy chosen by Haruhi to play the role of "mysterious transfer student". And so the SOS Brigade is born! Things only become weirder and more difficult for Kyon, however, when he finds out the Haruhi has unknowingly surrounded herself with the very people she has been wishing all this time to discover: Nagato Yuki's actually an alien, Asahina Mikuru's a time traveler, and Koizumi Itsuki's an esper! And why have all of these people appeared in the first place? Why, for Haruhi, of course! Three years ago, Haruhi caused some sort of disturbance that each one of them finds worth investigating. And Kyon, for whatever reason, seems to be the only "normal" one in the whole group. His biggest question: why him?
Flunk Punk Rumble AKA: A Yankee Boy and Glasses Girl; Yankee & Glasses Girl; Yankee-kun to Megane-chan
Shinagawa Daichi is a high school delinquent who just wants to be left alone. However, class rep Adachi Hana wants to be friends with him, but Shinagawa doesn't want to. Shinagawa finds Adaichi extremely annoying and he can't seem to get rid of her, so they become friends anyways. Full of comedy and a tad bit of romance.
Pastel Poor Mugi Tadano(plain wheat) . . . The sixteen-year-old is heartbroken after his girlfriend moves away. To ease his troubled state, Mugi takes a summer job at his friend Kazuki's beachside snack bar/hotel on a tropical island. It seems like the perfect plan-until Kazuki sets Mugi up on a date with Yuu, who's supposed to be, well, a little less than perfect. When Yuu arrives, however, she's not the monster that either of the boys had imagined. In fact, Yuu is about the cutest person that Mugi has ever seen. But after Mugi accidentally walks in on Yuu in the bath, the girl is steamed. When trying to apologize the next day, he discovers that Yuu has left the shores of paradise. Mugi vows to search high and low for the beautiful Yuu, but will he ever see her again?
--Note this manga is NOT about searching for her!--
Fairy Tail Lucy is a 17-year-old girl, who wants to be a full-fledged mage. One day when visiting Harujion Town, she meets Natsu, a young man who gets sick easily by any type of transportation. But Natsu isnt just any ordinary kid, he's a member of one of the world's most infamous mage guilds: Fairy Tail.
Gokusen Yamaguchi Kumiko is the granddaughter of a Yakuza boss and is completely at peace with the fact that she is the heir of her grandfather's empire. However, she leaves most of that up to the rest of the family and their talented lawyer, whom's she has more than a slight crush on. Instead, Yakumi works hard to fulfill her hearts desire to be a teacher. But she must hide her background so she doesn't get fired from her first teaching job, which is at a school filled with tough kids and difficult students.
Historys strongest disciple and historys strongest disciple Kenichi basically the same story, second one incorperates the first with little bit different circumstances.
Shirahama Kenichi is a book lover who has just entered high school, but he is often bullied by others. One day, he became good friends with the new transfer student, Fuurinji Miu, who was also looking for a friend. Kenichi was shocked at how powerful she is at first, but he is still somehow attracted to her...
To view these and many more that i have read and am reading check out MyManga list here http://myanimelist.net/mangalist/lacktorium 
