If you didn't have HBO in the mid to late 80s you may have missed this craptacular gem, so here's a primer.

Those of you who have seen this one know exactly why it rules. Everyone gets hopped up to see a close encounter with a comet and dammit if it doesn't turn out to be a killer zombie-creating comet! The only survivors are those who took refuge in iron (or steel? I can't remember) rooms. Everyone else is either dead or lumbering around the streets as a zombie.