Im a huge metal fan, but my best mate is obsessed with rather upbeat happy rap so it kinda gets on ya. Only listen to about 5 or 6 rap songs though.
Metal:
It Dies Today, Misery Signals, Mudvayne, Fury Enfolds(brothers band), I Killed the Prom Queen, As I Lay Dying, Inked In Blood, Neaera, Ligeia, Killswitch Engage, I Got Shot in the Face./ list could go on for hours.
Rap, few songs by:
Ice cube, Lil jon, 8 Ball, Kottonmouth Kings.
Electronica/Dance:
Anything hardcore dance. Some hardstyle. Not a fan of the soft stuff.