Whether Christie ever had an affair or not won't matter to most voters in a general election. In the GOP primaries it will be a big deal. I disagree with Christie on many issues, but he proved himself to be very competant in an emergency situation. That counts for a lot in my book.
Hillary is also a known quantity. I would like to see a contest between them, and hear them both lay out what directions they want to move this nation in for the next decade, and what their policies would be to move the nation in those directions. The only other person the GOP has that has the brains to go one on one with Hillary is Huntsman. A good man with a good record. The rest of the field is clown car material.