Harley had like a billion alternate outfits in BoP (and a few in SS, most of which were cut) so I just went with the noteworthy stuff.

The black and red leather from TSS is my favourite of the bunch. It looks true to her brand while being a practical adaptation that looks believable and aesthetically pleasing.

The first suit she wore in The Suicide Squad was so fucking clean it needed to be used more. And I'm gonna come forward and say I hated her appearance in Suicide Squad. It is not very "Harley Quinn" and it just looks like it was thrown together in a thrift shop. And that flashback suit in that movie is just so weird and wrong alongside the ugly ass design of Jared Leto's Joker lol. Close second place on my list is her red dress suit in The Suicide Squad because I find it fitting that Harley can still kick absolute ass whilst wearing such restraining garments

The Suicide Squad

Red dress