I've mentioned it before, but I'm a sucker for British science-fiction shows. When Torchwood first came on, I was just getting into the revival of Doctor Who, so I happily started watching the spin-off as well. It's not the greatest show, but still has some really fun moments in every episode, regardless of how cheesy it gets.
The sixth episode of Torchwood opened with "Monster" by the Automatic (or the Automatic Automatic for those of us in the United States), and it perfectly set up the goofiness that had already occurred and would follow in each episode to come. From alien lizards to Cyberwomen, the episodes play out like a midnight b-movie with a better budget and effects. John Barrowman is awesome as Captain Jack Harkness.
The hook of "Monster" gets stuck in my head easily with its paranoid chorus and pogoing guitars. That's a perfect earworm.