"Code Monkey" is the song that first got me (and a lot of other people) into Coulton's work. It's cute, it's funny, and it's catchy as hell. Booth's version visualizes the song pretty well, though I'm not sure why when Coulton says "Tab" we see what looks like cans of Horde (with Taurine?).
"Re: Your Brains", on the other hand, was a totally new song to me, but I love it already, and it's perfect for the WoW treatment. Blazing quote of glory: "All we want to do is eat your brains/We're not unreasonable; I mean, no one's gonna eat your eyes". If someone made a parody of the excellent comic The Walking Dead, and that parody had a theme song, this would be it.