I don't care much for hardcore music, but I do really love some progressive/speed/power metal bands! These include Blind Guardian, Serenity, and my absolute favorite band ever, Kamelot!
Tons of bands in this genre have the same sound, but these three bands have their own distinct sound, and are, in my opinion, leading the genre in a better direction.
Here's some links to a song from each:
Blind Guardian: https://www.youtube.com/watch?v=0WXeHT661xM
Kamelot makes a lot of concept albums that usually have a supernatural aspect such as demons, or the afterlife, and their music is absolutely divine.
Serenity makes music about a lot of historical events, which is pretty cool, but they make amazing use of symphonic music which is what sets them apart.
Blind Guardian writes mostly fantasy stuff. They are absolutely brutal, but they can also slow it down and play some music that I could imagine bards from medieval times playing.