Congratulations you just blew my mind. You just critiqued Naruto for being filled with filler, and having too many episodes. Are you unaware that just Dragon Ball Z had nearly 300 episodes, and the series was notorious for filler content. That is what the pot calling the kettle black. Naruto basically has eighty fewer episodes, and the filler is largely avoidable. Most of it comes at the end of the series, and you can spot a filler episode in five minutes. Not trying to be obnoxious, but wow it really is comparing apples to apples.
I suppose I might recommend that if you haven't you should watch the Dragon Ball series. You know the series that came before Z, and Dragon Ball GT the follow up series, and Yu Yu Hakusho. That there should get you a solid three hundred episodes of entertainment. They are all basically the same thing. So you should enjoy all of them.
How do you go from Dragon Ball Z to Death Note. Thats like doing a complete 180. Damn near impossible for me to give you a good recommendation. You either don't care at all what you watch, or you have a very quixotic personality. That is kind of like saying I am a huge fan of Sesame Street, but I am very interested in hardcore porno with real heavy focus on fisting action. These series can't be any further apart on the spectrum.