My friends that I discuss D&D with have often had (somewhat long) discussions about which alignment so-and-so would be. This discussions can get very interesting, and I thought I'd carry them on over to here. I'll start by listing an alignment and characters whom I believe to be prime examples of that alignment, so here goes...
Lawful Good: Superman, Captain America, Kenshin Imura, Bright Noah, Obi-Wan Kenobi, Brienne of Tarth, Ned Stark, Optimus Prime(Michael Bay's version is more LE imo).
Neutral Good: Spiderman, Harry Potter, Frodo, Gandalf, Amuro Ray( After the first Gundam series where he was more TN), Luke Skywalker, Finn l'avventuriero(Adventure Time).
Chaotic Good: Robin Hood, Wolverine, Kamina, Judau Ashta, some incarnations of the Doctor.
Lawful Neutral: Judge Dredd, inspector Javert, Rorschach(Watchmen), Mosès the dog(Lupo Alberto).
True Neutral: Shinji Hikari, Doctor Manhattan, Galactus, Taskmaster.
Chaotic Neutral: Elric of Melnibonè, Conan the Cimmerian(at least in the early stories), Deadpool, Jack Sparrow, Lupin the 3rd.
Lawful Evil: Darth Vader, Doctor Doom, The Titans from Zeta Gundam, Haman Karn, Megatron, Sinestro, Daleks and the Cybermen
Neutral Evil: Raistlin Majere, Saruman, Sauron, Loki( Marvel), Larfleeze, Thanos, Palpatine, Sephiroth.
Chaotic Evil: Joker, Gregor Clegane, Ali-Al Saachez( Gundam 00), LOTR's Orcs, Crazy Steve(Frank Miller's version of Batman), Carnage, the Lich(Adventure Time), Kefka.