Fairly even. The debate's focus was supposed to be foreign policy, but the first 40 minutes were taken with discussions around the economic crisis and bailout plan. Both candidates were impressive in different ways each. McCain who earlier this year admitted his weak points were on the economy, gave reasoned, prepared responses, agreeing with moderator, Jim Leher, and Obama, that there had to be spending cuts, to especially deal with the $700 billion proposed bailout. Obama generally agreed but notably differentiated with McCain on the method of program/spending cuts by saying, I propose we cut using a scalpel rather than a hatchet - a poke at McCain's supposed simplistic method of spending and program cuts.
On foreign affairs, Iraq and Afghanistan, McCain certainly appeared to be comfortable, though his experience, credibility, and voice of conviction did not knock the ball out of the park. Obama showed that he has been studying, and was knowledgeable of foreign affairs, been advised on "new" approaches to foreign relations by more immediate Presidential talks with enemies (according to him, from McCain's advisor Henry Kissinger). He even criticized McCain on his and Bush's stalwart emphasis on Iraq while, as he contested, the real focus of the war against a Taliban-lead terrorist war, was in Afghanistan, where the Taliban have grown and gotten more aggressive. Obama's arguments sounded valid, and not like someone who was as naive as McCain's team would have liked for him to appear.
Overall, there was no clear winner. At first, Obama came out swinging more so than McCain, but McCain's coolness acted like a rope-a-dope.