Here's my take...
Allison was my favorite ever since she sang Alone in the semifinal round. It's stupid that she's not still in it, but she and Adam were probably drawing from the same fan base, so she lost votes. I think she'll have the best career out of the group.
Kris Allen is easily my favorite remaining, and his Heartless last night was by far the best of the night. He has a chance to be pretty successful, in a Jason Mraz sort of way.
Gokey seems to have faded. He's good, but he's Taylor Hicks without the gray hair and the strange mannerisms. I wonder how different these performances sound live, because I didn't think his second performance was as great as the judges did. It was good, but boring.
And I just don't get Adam Lambert. I understand how amazingly talented is. There's only a few people on the planet with that kind of range. I would guess he was incredible in Wicked. But I don't see him as commercial. His performance of One and Cryin' just left me wishing I was listening to the original version instead. He does that screech thing way too much. Just because you can do it doesn't mean you should all the time. And he seems like a pretty nice guy in his interviews, but I'm totally put off by the way the judges and producers pimp him to the audience. They let him close the show almost every week. He got, by far, the best "judge's choice" song. He gets better lighting and camerawork. And now he has Simon openly campaining for him. It's like he's the Obama of American Idol. He's beyond criticism.