Naruto vs. Bleach has always been a tough one for me. Naruto kept a coherent and interesting plot for a lot longer than Bleach did, but I'd also argue that the nadir of its plot is far lower than Bleach's. Naruto's plot became incomprehensible and weird while Bleach's plot just got kinda boring. Naruto also went through a succession of increasingly more annoying primary villains after Pain and Orochimaru left the picture, while Aizen had a certain flair that kept him from being totally forgettable. Bleach consistently had better fights, but it also had some really annoying secondary characters that Naruto was never plagued by. Naruto's final drag to the finish was much longer than Bleach's, but Naruto actually finished the story properly and had an actual epilogue arc that went through and gave us closure for all the characters. Not to mention The Last.
Thinking about it even now I can't decide between them. There's good elements in both, and absolutely terrible elements, and what is good and what is terrible varies depending on both the show and what point in the show you're at.