Personally felt it could have been darker, grittier and more depraved. Unsure if whether this is due to there being removed scenes(?) or not as the movie was only rated NC16 in Singapore (where I watched it) and Is supposedly to be rated R elsewhere.
Joaquin Phoenix's acting was spectacular, You could feel his raw emotions and the slow long burn throughout the movie into his final transformation to the joker. You can sympathize with Arthur and feel him throughout the movie.
The ending was weak because of unneeded scenes they added, like the last 5 minutes of the movie served no purpose. In my opinion, the perfect end would be the scene where Arthur paints the iconic Joker smile on his face and have the movie fade to credits there.
75/100 score from me