Personally, I think Julian Castro was quite powerful and second runner up has to be the remarkable Tammy Duckworth. Castro is incredibly smart and realistic. In my opinion, he kept it real. He pointed out clearly the challenges that Obama has faced and reminded us that he made the decisions even when they weren't popular, to save jobs and end a war. He made a good case that Obama genuinely cares about people and Romney cares about his own financial security. He made good arguments of what Romney failed to do for the state of Massachusettes.
Tammy Duckworth has to admired. She too is remarkably bright, having the career as a blackhawk helicopter pilot in combat. She sacrificed her limbs for our freedom but never let the sacrifice make her bitter. She rose to the challenge and stood before the convention on prostehesis, a proud Veteran! Her argument for Obamas support of our troops and their families was stunning.
The best is yet to come though, I think. If Bill Clinton is true to form, he's going to take it home tonight.
Footnote: Interesting, isn't it, that NotPC thinks he heard Bill Clinton already. What convention was that?