Honestly I'd say I'd prefer Naruto over DBZ. In my opinion Naruto did a better job with its character development than DBZ, and had more of a "story" per say. Now if this included DB as a whole I might be inclined to side with it due to how awesome part 1 was but Z on its own is a pretty basic story. In fact I'd go as far as to say there isn't really a story, it's a pretty repetitive formula of enemies invade Earth, heroes fight them off with some casualties, heroes proceed to attempt to bring back dead friends and get into more trouble, rinse and repeat till the end.
However, I'd like to point out that I'm not a Naruto fanboy. To be frank, I'm not all THAT fond of Naruto either. In elementary school I thought it was the greatest thing I had ever seen and worshiped it like no other. Partially because back then it was in its golden age, and partially because I was a child that Naruto was pretty much made to cater to. Naruto is a very Shounen story, easily as much as DBZ is, and I've come to realize that there are many more animes that are loads better storywise and characterwise than the average Shounen. I'm still a big fan of part 1 but part 2 has a huge amount of problems. In particular I very much dislike Sasuke and find that the development that seemed like an attempt to make him sympathetic only made him feel more like a scumbag and it bothered me that, for a time, he hogged the screen (er, panel) time. But it is balanced out by awesome developments like Kisame's role in part 2, the exploration of the stories of Minato and Kushina, etc.
And on the topic of fillers, aside from when I was a kid, I hardly watched through the Naruto anime (and have seen practically none of Shippuden to be honest). Pretty much everything I have knowledge wise for it is from the manga so the filler doesn't really pertain to me.
