1. Brian Moser - The Ice Truck Killer - Season 1
And last, but certainly not least, we come to the best foe Dexter has had to face: his own brother, The Ice Truck Killer. I mentioned that Trinity was missing one aspect that I believe puts ITK above him: the personal connection to Dexter that makes the first season of the show so magnificent to watch. Yes, Trinity commits the most shocking murder in the entire series, but the revelation that Brian Moser is Dexter's older brother changed Dexter's character forever. The two brothers were separated when Harry chose to save Dexter from the shipping container where their mother was murdered, and leave Brian behind. Harry believed that Brian was too damaged to be saved, which arguably led to him becoming the ITK. Both brothers ended up becoming serial killers, but Dexter had one thing Brian didn't: Harry's code. The dichotomy of the two characters is fascinating, especially considering that the final reveal happens in the season finale. Throughout the season, ITK has been toying with Dexter, leaving him clues and cryptic messages at crime scenes and on his own doorstep. I would argue that the show has failed to reach the same level of brilliance that is displayed in its first season, as Dexter's fascination with ITK makes him question his own methods as a killer. As the season drew to a close, Brian kidnapped Deb, hoping that he and Dexter could kill her together and be reunited as brothers. Instead, Dexter turns on his brother and kills him, staging it to make it look like a suicide. It's a heart-wrenching, emotional, and pivotal moment when Dexter sits in the corner of the room, crying, as he kills the one man on Earth who can truly, and fully, understand him.
Memorable Moment: Proposes to Deb, then knocks her out and puts her in a kill room for Dexter.