I like anime and I know ones with multiple personality/identity stories.
I have decided to list them here and grade their dissociation portrayal.
Yu-Gi-Oh!; A for original story, B for spin-off stories
Mitsume ga Tōru; B just because it has not quite sit with me
DNA2; A if take in mind that it is some bland of OSDD and DID elements
DNAngel; B because they do not delve that much into DID/OSDD elements
Rosario+Vampire; A ...