Just a curious thought I had recently. Naruto has been in an awful lot of fights but I can't recall if he ever actually killed another person.
Technically speaking, Naruto never landed the killing blow on anyone.
- Haku, even though beaten by Naruto, jumped in front of Kakashi's Raikiri.
- Kakuzu, hit directly by the Rasenshuriken, survived, and later killed by Kakashi.
- Pain's bodies were already dead. Nagato, the living puppeteer, sacrificed himself after hearing Naruto's resolve, with the Rinne Tensei, and revived all the people of the village.
You could say that Naruto was a major cause in all of these people's death, but he did not directly kill any of them.
I know that this thread is old, but I just want to point out that Naruto did kill Aoi Rokusho with the Rasengan. Aoi Rokusho is a rogue ninja who ran away from the Leaf Village with the sacred Thunder Sword that belonged to the 2nd Hokage. Naruto attacked the Thunder Sword that Aoi sensei was using and that sent Aoi sensei plummeting down the cliff, which according to Aoi himself, is a fatal fall. This was during their mission to the Land of Tea (*ep 106 in Naruto). I think that's the closest thing Naruto has to killing somebody on his own without any variables.