I do not have DID but I happened to see this topic as I was scrolling down the forum index and thought I'd share my experience with "Dexter" for you.

I have Paranoid Schizophrenia, and I absolutely love this show. It does not trigger me into psychosis but it does make me think about my own situation. It's strange how much I can connect with a fictious character, but I do. I know what it is like to hide and pretend to be normal. To wear a mask so to speak. I know exactly what it is like to have this running comentary in my head as this character of Dexter does to explain what he is feeling to the viewer.

It's one of those things I simply cannot turn off, even if it does a bit bloody, I just sit and stay glued to it. I am not quite sure why.