Soul Eater - "Resonance"
When I first started watching Soul Eater, I really didn't know what to expect, but this song really set the tone for me. Soul Eater rarely slows down for its audience to catch up, and the song compliments the action-centered plot. The video also serves as a slightly enigmatic, but fully developed introduction to all of the main characters, both good and bad (Medusa's creepy dancing is absolutely perfect). While the second intro song, "Papermoon" is also excellent, nothing will ever quite match up to the power of the first song, I mean, even Death can't help but dance.