Probably Naruto. he has kyubi and sage powers, not to mention is rasengan shuriken thingy. i would say sasuke too but he got his ass kicked by the eight tailed beast guy , plus i think hes a noob anyway. :)
Well, if you're talking about a characters greatness in regard to his coolness factor the it would be either Kankuro or Sasori.
But if you're talking about surviving a fight then I think it would be Orochimaru. You can't kill that guy. No one can. Many have tried, all have failed. Plus he could just create some new, unexpected, never before seen jutsu that perfectly countered whatever your freaky talents you have. It might take him a hundred years to create it... But I haven't seen any instace in either the manga or anime that would indicate it being a problem.
After reading the last chapters of the manga I just became a huge sharingan fan. Sasuke is growing so powerful so fast. All these amazing Sharingan techniques are so damn awesome However Im afraid hes going to go blind like Madara said.