Loved it! Liked the live action movies, too--just different enough from the anime and the manga to be interesting. Even the L-centric spinoff film (L: Change the World) wasn't *that* bad. (To anyone who has read the manga and watched the anime--did you prefer one over the other, or do you think they can both stand alone?)
The writing alone is incredible; Every time I thought they might paint themselves into a corner plot-wise, they pulled out of it with an amazing twist...very well executed. Have not read the manga, only watched the Anime and none of the Live action.
As a friend said to me recently, this is one Anime I would recommend even to non-Anime-fan people.