I know I'm late to the party, but the stand out moments to me where Arthur in his apartment, getting ready for the kill....his face all white (even his tongue) and him walking around shirtless, ready to kill with those scissors. Very simple, but very unsettling look.
If Hot Toys ever did figures, the full suit and make up version is a must, but I think the shirtless, stark white face version splattered with blood would be a great variant.
And yeah, he looked way cooler than I thought he would once he went full Joker. From way back when we saw the first still, I hated the blue highlights and red nose, but absolutely loved the color and tailoring on the suit. Seeing it in motion, especially the iconic stair dance, it totally won me over.
Those two looks were the best for me, but I think the all white psycho look splattered with blood was my favorite look and scene in the movie.