Ugh, I wouldn't go nearly that far. Death Note was at the very least watchable, but it wasn't remotely the sort of intellectual fare that so many of its fans hold it up to be. All it really did was replace the standard sort of shounen power-up posturing with the equivalent overly-verbose dialogue posturing. I remember that one episode where Light and L were playing tennis against each other, and their inner monologues were literally that meme image of "Now it is I who am behind you!" It was completely insufferable writing. Then there was the fact that the authors disposed of one of the best elements of the story at the halfway point and had absolutely nothing of consequence to replace them with, which just smacks of narrative incompetence. But what frustrates me the most is that the series never made any pretenses at making any sort of judgement, whether positive or negative, on Light's actions. The authors have admitted as much too. If you're going to create a character like Light, at least have the balls to make some sort of statement about him.
Let's call a spade a spade: Death Note was a mostly standard shounen with unique window dressing and an insufferable twat of a protagonist that managed to squander the very real potential it had. Now if you want a truly-good cat-and-mouse game that actually dwells on the nature of evil, go watch/read yourself some Monster.