emotionl rock.
Groups like "the best band in the world" (acorrding to the likes of Kerrang) My Chemical Romnce, Aiden, Lost Prophets.
Or taken from wikipedia
At the end of the 1990s, the underground emo scene had almost entirely disappeared. However, the term emo was still being bandied about in mainstream media, almost always attached to the few remaining 90s emo acts, including Jimmy Eat World.
However, towards the end of the 1990s, Jimmy Eat World had begun to shift in a more mainstream direction. Where Jimmy Eat World had played emocore-style music early in their career, by the time of the release of their 2001 album Bleed American, the band had almost completely removed its emo influences. As the public had become aware of the word emo and knew that Jimmy Eat World was associated with it, the band continued to be referred to as an "emo" band. Newer bands that sounded like Jimmy Eat World (and, in some cases, like the more melodic emo bands of the late 90s) were soon included in the genre.
2003 saw the success of Chris Carrabba, the former singer of Further Seems Forever, and his project Dashboard Confessional. Carrabba's music featured lyrics founded in deep diary-like outpourings of emotion. Where earlier emo had featured lyrics of a more dark and painful direction, Carrabba's featured a greater focus on love won and lost and the inability to cope. While certainly emotional, the new "emo" had a far greater appeal amongst adolescents than its earlier incarnations.
With Dashboard Confessional and Jimmy Eat World's success, major labels began seeking out similar sounding bands. Just as many bands of the early-to-mid 1990s were unwillingly lumped under the umbrella of "grunge", some record labels wanted to be able to market a new sound under the word emo.
At the same time, use of the term "emo" expanded beyond the musical genre, which added to the confusion surrounding the term. The word "emo" became associated with open displays of strong emotion. Common fashion styles and attitudes that were becoming idiomatic of fans of similar "emo" bands also began to be referred to as "emo". (For further discussion, see Emo (slang).) As a result, bands that were loosely associated with "emo" trends or simply demonstrated emotion began to be referred to as emo.
In an even more expanded way than in the 90s, emo has come to encompass an extremely wide variety of bands, many of whom have very little in common. The term has become so broad that it has become nearly impossible to describe what exactly qualifies as "emo".
Correctly or not, emo has often been used to describe such bands as
AFI, Alexisonfire, Brand New, Bright Eyes, Coheed and Cambria, Death Cab For Cutie, Fall Out Boy, From First to Last, Funeral for a Friend, Hawthorne Heights, My Chemical Romance, Panic! at the Disco, Senses Fail, Something Corporate, The Starting Line, Story of the Year, Taking Back Sunday, Thursday, The Used, and Underoath.[8] The classification of bands as "emo" is often controversial. Fans of several of the listed bands have recoiled at the use of the "emo" tag, and have gone to great lengths to explain why they don't qualify as "emo". In many cases, the term has simply been attached to them because of musical similarites, a common fashion sense, or because of the band's popularity within the "emo" scene, not because the band adheres to emo as a music genre. (The revulsion of some bands from the term emo is not unlike the retreat from the genre by the bands in the indie emo scene near the end of the 90s.)
As a result of the continuing shift of "emo" over the years, a serious schism has emerged between those who relate to particular eras of "emo". Those who were closely attached to the hardcore origins recoil when another type of music is called "emo". Many involved in the independent nature of both 80s and 90s emo are upset at the perceived hijacking of the word emo to sell a new generation of major label music. Regardless, popular culture appears to have embraced the terms of "emo" far beyond its original intentions.
In a strange twist, screamo, a sub-genre of the new emo, has found greater popularity in recent years through bands such as Thrice and Glassjaw. [9] The term screamo, however, was used to describe an entirely different genre in the early 1990s, and the new screamo bands more resemble the emo of the early 1990s. Complicating matters further is that several small scenes devoted to original screamo still exist in the underground. However, the new use of "screamo" demonstrates how the shift in terms connected to "emo" has made the varying genres difficult to categorize.
Even still, the difficulty in defining "emo" as a genre may have started at the very beginning. In a 2003 interview by Mark Prindle,[10] Guy Picciotto of Fugazi and Rites of Spring was asked how he felt about "being the creator of the emo genre". He responded: "I don't recognize that attribution. I've never recognized 'emo' as a genre of music. I always thought it was the most retarded term ever. I know there is this generic commonplace that every band that gets labeled with that term hates it. They feel scandalized by it. But honestly, I just thought that all the bands I played in were punk rock bands. The reason I think it's so stupid is that - what, like the Bad Brains weren't emotional? What - they were robots or something? It just doesn't make any sense to me.".
Or just watch this. Sums it up !
http://www.youtube.com/watch?v=ggK0ekmWJfY