No spoilers - Only the first two seasons of this anime have been dubbed in English by Funimation, an excellent organization that does quality work bringing anime to American audiences, but sadly, those two seasons of the four that were produced by Dentsu and TV Tokyo, are nowhere near as well done as the last two.
The first two seasons, which this review addresses, loosely follow the manga, but include extras and filler that don't have the clarity or maturity of the source material. These extras may come from other peripheral publications that this reviewer hasn't seen, but they bog down and trivialize the story almost to the point of making it boring. I've now seen all the anime and read the available manga (which continues the story long past what has been animated) and the shortcomings of the first two seasons of the anime are GLARING.
D. Gray-Man, seasons 1 & 2, are worth watching if only for the wonderful dubbing work that Funimation does, but their only real purpose is to set up the situations, characters and storyline for the third and fourth seasons. It's a shame that Funimation has not bought the rights to these subsequent seasons, partly because of a lack of enthusiasm for the first two (which is, IMHO, warranted) but also because Dentsu is asking (so I am told) a great deal for the rights to the later seasons, because if the first seasons of DGM had followed the manga as closely as the third and fourth seasons have, I believe it would have been a smash hit.
I find the first seasons watchable, but only once. While I'll go back time and again to watch episodes from the third and fourth seasons, the only episodes from the first two that I can watch again are the ones that most closely follow a chapter in the manga. The fillers bore me silly.
This series is worth a watch, but if you want to do the world a favor, add your voice to the people asking Funimation to buy the rights to and dub the later seasons. I call the first two seasons of this series a 7, but the last two are 12's!
