I think we're all pretty much agreed that Ryuk is an EXTP.
Yagami Light: INTJ
L: INTP/INTJ
Mello: ENTJ
Misa Misa: ESFP
Near: INTP/INTJ
Rem is a complete idiot. Probably an ESFP like Misa Misa, or an ISFP. I also always wondered how they knew Rem was a girl. It was like just looking at her they could tell, but I couldn't. I first thought she was definitely male.
Why were all the women in this series SO stupid? I loved this series, but that irritated me.
Other than that, I wish it would have gone on longer. L is by far my favorite character in any series.
I also wish that Light had had a vulnerability, or an emotion I could relate to. L appealed to me so much as a character because he did experience sadness, and he did see flaws in himself. He also felt a certain fondness for Light, and admitted that Light was the only person he'd ever come close to befriending. Light saw no flaws in himself, and I never saw an emotion other than fear and anger in him. I could not relate to him because he was never vulnerable or human. Sure, he was a psychopath, but even psychopaths have vulnerabilities. Maybe he was a megalomaniac. Anyway, he was an incomplete, unsatisfying character by the end of the series. He wasn't really human, because he never had the uncertainty or sadness that I think every human has.