Palin fired up the base -- and turned off a lot of people who weren't in the base. I personally thought she gave a great speech at the Convention, and then it turned into that long, downhill slide where her lack of...uh, grey matter was exposed.
McCain's biggest <Nope> was refusing to make the cause of the Great Recession into an issue. He had a potentially winning issue because he'd sponsored a bill to reform Fannie Mae and Freddie Mac back in 2005, and Obama and the rest of the Dems exposed it. Had he hammered that issue "I saw this coming and tried to stop it, and my opponent was on the wrong side", he may have had a chance. But he openly said he didn't want to cast blame for the bank problems because it needed a "bipartisan solution", so he dropped that issue.