Badass Decay: In Ancient History, Ghost Tucker isn't as powerful as Tucker was when he had ghost powers. Justified as Danny believes that when he separated the ghost from Tucker and broke Desiree's spell, it De Powered Ghost Tucker.
Broken Base: Despite the series' popularity, many fans are divided on the concept of Sam having ghost powers.
Growing the Beard: Following A Family Thing, the series seems to be coming into its own. Even Word of God has said that it was the story where the series would start really forming.
Hilarious in Hindsight: To those who have read "A Family Thing" and seen the T.U.F.F. Puppy episode "Sweet Revenge", you may notice that one of Butch Hartman's writers thinks a lot like the author or one of his assistants.
Squick: In-Universe example. Tucker and Valerie were visibly creeped out seeing Danny and Sam making out while Sam was dressed as Danny. Of course, many viewers have this same reaction upon seeing the pic the author drew depicting the scene.