One cliche I don’t like is how whenever you do a show that has a different villain every week (aka, Monster of the Week according to TV Tropes), I don’t like how it’s clearly obvious you can figure out who the villain is, even before the show actually showed you who it is.
Why do I think it’s bad? Well let’s say you see some side character that plays a major role in a episode, and you never seen him before. Chances are he/she is most likely the villain.
So that way, when it’s revealed the guy you knew was the villain was in the beginning, is the actual villain, it really takes the fun out of guessing who the villain of the episode is.
Also, some examples I’ve seen the cliche in was Scooby-Doo and Bonkers (hey, even if I think Bonkers is a good show, I still don’t like how the cliche I mentioned is attempted in that show).