1.) Kabuto, I've hated him since pre-time-skip. He's a jerk. I can live with Tenten sucking because you're naturally going to have elite and not so elite, litotically speaking (i.e. understatement). He's so snotty and is currently strong only from using someone else's powers (Orochimaru, love whoever called him Oreo).
2.) Sakura kind of pisses me off because she could be so much more than what she is but nobody really trains her to harness her potential except her short time with Kakashi and the Tsunade. She has zero combat jutsu, just freakish strength from chakra control/release. She's a bust outside of medicine. Tsunade at least has some really powerful jutsu, but compared to Naruto and Sasuke, Sakura stopping advancing after the time-skip.
3.) Whoever the hell taught KillerBee how to rap. It makes his dialogue tiring at times.