So would you say that the people on the ferries were better than Harvey, or that the Joker just "pushed" him harder?
You all make an excellent point that the Joker doesn't care about himself. And while he didn't get the widespread chaos he wanted, he nonetheless did **** up arguably the two people who mattered most.
That's why its a win AND lose for the Joker. He accomplished everything he himself set out to accomplish - it just didn't have the effect he expected it to. I think an ideal ending for the Joker would have been: Dent goes on a killing spree, it destroys everyone's hope of ever having a clean city, and Batman's only way of stopping the Joker is to kill him. The first thing went exactly how we wanted, but the rest didnt.
Honestly, with the way the Joker's character is written, he "wins" as long as something is in chaos, anarchy, etc. As he said, "I just do things..." I dont think he plans that far ahead, just enough to ensure things will still suck for everyone.