Another metal-lover here, though I also dabble in electronic and industrial, especially bands that combine these. With a guilty pleasure for vocaloid but let's forget about that (although some of the Luka users on YouTube occasionally cook up something awesome...)
Bands I am currently listening to in no particular order:
Dir en Grey - This song is kinda Japanese death metal but they vary a lot
Crossfaith - metalcore with an electro/dance vibe
Feed Her To The Sharks - Melodic Metalcore
Heart of a Coward - Meshuggah-y prog metal
Sylosis - Thrash of a more traditional bent
Blood Stain Child - Japanese blend of metal and trance, inspired by In Flames
SiM - Japanese metalcore/punk/reggae combination. Whatever it is, it works:
Bury Tomorrow - Metalcore
Exist Trace - Female Visual Kei Metal Band. They vary in hardcore-ness but this is a good-un:
Also Happy to see Periphery and Hacktivist mentioned previously, as they feature a LOT on my music player right now. Favourite songs (which don't appear to have been mentioned) are Elevate for Hacktivist:
and Ragnarok for Periphery:
Hope my additions are worthwhile :)