Sasuke killed Orochimaru, a few Samurai and Danzo.
Sasuke would have killed Danzo but he used that sealing technique to prevent Tobi from getting his hands on his eye, so that one should count as Sasuke was the one who drove him to that fatal point. Similar thing with Deidera. He also killed White Zetsu and lots of his clones. He also would have killed Karin if it wasn't for Sakura arriving.
The main thing is though, is that he has killed more people than Naruto has or ever would for that matter.
