I was going to say Walls of Jericho but someone beat me to it lol ... they are on TrustKill records... also try out Atreyu (there considered metalcore no?) and Crisis... you might also consider the band Cro-Mags.. its a old school band from the 80's but they tended to be metalcore at times... especially there first album and to a certain extent releases after that if you can find their albums... probably on ebay u can find them..
Not sure if you guys will consider ALL of these metalcore....
god forbid
burnt by the sun
heaven shall burn
martyr ad
mastodon
with dead hands rising
psyopus
ion dissonance
the number 12 looks like you
through the eyes of the dead