I need to say, after watching the movie again recently, that Bumblebee and Optimus Prime run Jazz very close for my vote on this, I know I cant officially change it, but both Prime and Bumblebee were superb in this movie, and the most accurate throughout as well.
Jazz still gets my vote, mainly because of that one powerful scene were he takes on Megatron in the absence of Optimus while facing overwhelming odds, and doesnt run away like Ironhide and Ratchet do. I also like how, throughout Bumblebee's capture, Jazz is the only one that seems to care about him, and setting him free. But my vote is closer now than it has been in the past.
Either way, Jazz, Prime and Bumblebee were far cooler, noble and more likable than Ironhide and Ratchet in this movie for me.