well, you migt have heard of them and you might think (as a lot of people) that their music is too "violent" but i love them :) it is true it is not the kind of music i would listen to every day and so often.
I think they have had a great evolution through the years, you can really hear the difference between their first album and the lattest one (their 3rd one).
A few facts : (from wiki)
Bring Me the Horizon are a British metalcore band from Sheffield, Yorkshire, who formed in 2004. They are currently signed to Visible Noise Records in the UK, Epitaph Records in the US and to Shock Records in Australia.
and so they realised 3 albums : Count your blessings in 2006, Suicide Season in 2008 and There Is a Hell, Believe Me I've Seen It. There Is a Heaven, Let's Keep It a Secret in 2010, which according to me their greatest so far (they've worked more on the melodies and stuff)
They are currently on tour throughout Europe I think, and they will be in my city (Lille) on the 6th of June and i'm really proud to help them with the promotion :)