There's plenty of good metalcore bands. Converge off the top of my head is one. Botch is decent too. I do like poison the well if they are even considered metalcore. Pig Destroyer is a great one, way more on the heavy side.
I just don't think it needs its own section because it's really not very related to metal, even if it's called "metalcore". It's more on the hardcore side with metal influences and aggressiveness.