Foley. Definitely Foley. An underdeveloped, throwaway character, that served almost no purpose in TDKR, whose death scene was almost laughable, since we, the viewer, had such little exposure to his character and because of that, had no emotional attachment to him whatsoever.
I don't understand why so many people hate Rachel. She was a huge figure in Bruce's life, showing him the difference between justice and revenge. She, like Alfred, was kind of a moral compass for Bruce. In TDK, (Even though he never read the letter) She told Bruce not to lose his Faith in people, and in the final Joker fight, that's exactly what Bruce didn't do. Everyone was panicking that the people on the ferries were going to blow each other up, but Bruce said, not once, but twice, that it won't happen, even mocking The Joker about it when his plan failed. His only concern was The Joker, he believed too much in the people of Gotham.
Rachel was Bruce's childhood love, and the one thing he had hoped for after Batman. Her death broke Bruce's spirit and changed him for years to come. She was a well-developed character who served a vital purpose in Nolan's Batman. How anyone can say she is the worst character of the trilogy is ridiculous.