Your Joker looks really cool, only two suggestions:
1) Try to tweak the specularity a little, since joker is in heavy makeup, i would expect his "skin" to be less oily, more dull. A more detailed bump map for pores and wrinkles really would do wonders too.
2) The upper lip looks a little fat, try to tone it down a little. The lower one, on the other hand, is perfect.
I really like your joke man, not many artists play him from the "90's long-haired vandal" trope, that I usually enjoy.
Thanks ratone, I highly appreciate your feedback... Will do the changes definitely.... It's just that I'm finding it a bit challenging since I'm a new user and kinda trying to figure everything out on my own than getting external help and tutorials... But I'm glad you like the joker... Hopefully you'll get to see the changes soon!!..