kinda basic but i think my favorite clown is Harley Quinn. i always loved arleen sorkin's initial performance for her, and then they went and gave the character a whole amimated series that goes so hard (for the first couple seasons anyway). she's such a fun kind of chaotic good murderhero.

on the other end, and yet right next door, the Joker has kind of become my least favorite clown. i think there are a lot of interesting uses of the character to explore why batman is kind of a bad person, but he's been played to death, become too popular and made too sympathetic for the wrong reasons, he's an icon for a kind of nihilistic pessimist overcurrent in society i despise. this just applies to new joker renditions though -- the animated series hamill joker and ledger and a couple others keep a special place in my heart.