Rises was the best, however TDK is considered the best just for Heath. Best film trilogy ever made though.
Fun Fact : Anne Hathaway came in to audition as Harley Quinn but then they told her she was auditioning for Catwoman. This means feminist icon Harley Quinn may of been in the movie for some point.
The Dark Night by far. It remains my favorite comic book movie of all time and is perfect from beginning to end. That said Dark Night Rises is also amazing.
Obviously The Dark Knight was the best out of the three, but my favorite was The Dark Knight Rises. I liked Batman Begins, but it dragged on for a long period of time. All of them are AMAZING, though.