Yes, I do think that there was maybe *some* media favouritism toward the Obama side, from *some* of the media. There are several reasons for this, but they don't necessarily imply that the media was out to destroy McCain and elect Obama. It was just a matter of circumstances in some cases, and a combination of poor decisions made by the McCain campaign and good decisions made my the Obama campaign in other cases.
1) For many years, McCain was a media darling. He had a very close and warm relationship with the media, and they were very favourable toward him. He used to hang out with them while campaigning, and speak freely to them all the time, and they loved him for it. During this campaign though, his advisors cut off media access to him, and his interactions with them were much less frequent and more closely monitored and manufactured. In all fairness, from what I've read, McCain didn't like this situation any more than the reporters covering him did, he used to enjoy the free and frequent interactions. But, he did go along with it, so who is to blame? Given all this, I'm sure that certain members of the media and their bosses were miffed.
2) The whole Palin debacle made things considerably worse. She was little known outside of hardcore political junkies and her own constituents. She was introduced to the McCain campaign as a sort of saviour, a fresh-faced rookie who would save his campaign and assure victory. Naturally, in this age of intrusive media, they (and we, the public) wanted to know more about her. The problem was, she wasn't properly vetted, and she had considerable skeletons in her closet. In some cases, bloggers broke stories about her, and the mainstream media followed up. I read things about her on blogs sometimes several days before mainstream media picked it up. Some of it turned out to be nonsense, like the story about her daughter actually having given birth to her youngest son. In all fairness though, MSM dropped that story fairly quickly after it was announced that her daughter was pregnant. Still, other stories they reported on were very valid, and there were lots of them: troopergate, her husband being a former member of the Alaskan Independence Party, questionable actions she had taken as both mayor of Wasilla and as governor of the state, and on and on. Further, once she was firmly in the campaign and began to make media appearances, these were clearly disastrous. And who did the campaign blame the failure of these appearances on? That's right, the media. Way to alienate a profession you need good will from, McCain campaign! This was an extremely stupid stance for them to take.
3) Overall, Obama ran a more positive campaign, hence, there were more positives to report on. Conversely, McCain's was overwhelmingly negative in comparison; negative in tone, and also, just poorly run. Reporters don't generally create negativity, they only report on what's already there, so they can hardly be blamed. Reporting about Obama's negatives was largely out of the way by the time the presidential election was underway - Hillary took care of that during the primaries. As a result, when the McCain campaign attempted to revisit any of those issues, they didn't get much media play because the stories had already run their course. This also had the additional result of making the McCain campaign appear petty and desperate.
4) Finally, it was an historical election, the best chance American has ever had to elect a black president. Things like that play very well with the media, so it stands to reason that they're going to give the candidate more attention - attention that ended up being mostly positive, given the lack of negatives to report about him.