I have mentioned before the opening scene to 28 Weeks Later, how it is heart-in-your-throat exciting. The theme song from this movie will induce the same feeling. Slowly building and ever louder, your adrenaline will start pumping. I believe this is the perfect song for a PEM since the slow start will help set the mode for your unit while the undead take notice of and then march towards your kill zone. Make this the first song on your list.