For my favorite clown I have to go with Shorty from Killer Klowns from Outer Space. Really all of them, but they have the most unique design. I love how the movie is basically just a collection of "what if this thing clowns do was evil?". Also gotta give a shout out to the People's Joker as both the funniest and most emotionally effective clown in history.

I started writing the sentence "my least favorite clown is probably" but then I couldn't think of a clown I didn't like so I'll come back here if one comes to mind.