I think I stand out as one of the few Heresy members who absolutely despises metal (most genres of it anyway) so I'm going to throw out a couple of great bands here.
Simon Wilcox - She's an amazing vocalist and unfortunately I cannot even find most of her stuff on youtube but here's a link to one of my favorite songs of hers. http://new.music.yahoo.com/simon-wil...etty--44290166
Sleigh Bells - Maybe they aren't too unknown but damn do they know how to throw down a beat. This is their most recognizable song and definitely one of their best. Check em out!
Skrillex and Bassnectar - These are probably more well-known in the dubstep community but they define the genre. Here are two of their songs that I love. If you like dub at all you have to know/get to know these bands.