Could you recommend me any modern heavy metal band that i might not of heard?

Probably heard of them but Killswitch Engage is pretty sick. Lazarus A.D. and Warbringer are badass if you're into pure thrash with mean riffs. For more melodic stuff, there's heaven shall burn, neaera, in flames, all shall perish, children of bodom (don't know what to classify them). Heavier stuff there is testament, strapping young lad, machine head and lamb of god.