The Dark Knight
Heath Ledger brought on a whole new background to the character of the joker. In the cartoons the man comes off as a cheeky, cliche villain in need of a descent wardrobe and hairdresser, but with Ledger's performance you can see that there is an actual source to his madness. Whether the scarring of his thoughts and face were done by his "wife" or father, we don't know, but the emotional scarring runs so deep that even at the end of the film one does feel a tad bit sad that the villain has been bested (of course it is the beginning of many).
This movie is centered around the character of Batman, but it seems that the main man was missing from his own movie. I believe the writers focused more on the physical aspect of the character, leaving Christian Bales performance somewhat dry. It was if batman cameoed in his own movie. And I have to say, I really hate his "batman" voice, it sounds like he's trying to imitate and chain smoker *gah*!!
Gary Oldman's character was probably the best to connect with!! He delivered a good, clean performance most likely done in order to keep himself from stealing the spotlight, but of course he still did. Even though he is famous for his psychotic roles in the past, Gary Oldman can still play a normal, sane person and still manage to make him stand out even when acting with the more well rounded characters.