Guys, try and put a bit more in your posts, I don't want to start handing out points here.
Converge - The Saddest Day
Unlike most Hardcore or Metalcore, this song actually goes for a while, 7 minutes. It has some fucking awesome riffs in it, two of which I can play. The buildup (one of said riffs) in the middle is easily the best part, there's just so much tension around that point...
