The thing is, come November, it doesn't matter whose names are on the ballot. We're already screwed.
You've got 3 people that are all the same running for the same position claiming that they are all different.
Vote for Hillary, she's got experience, and isn't Bush
Vote for Obama, he's new and different, and isn't Bush
Vote for McCain, he's a Republican, and isn't Bush
None of them have any plans that will actually help anything.
None of them would even be able to get their plans enacted because there is still a Congress
None of them will unite America
None of them will unite the world
None of them will fix Iraq/Afghanistan
None of them will fix health care
None of them will fix China/Iran/N Korea/Russia...
None of them will fix the environment
None of them will fix the US Dollar
At best some of them might provide band aids that could temporarily ease a symptom of one of those problems.
So I guess the best way is to choose whose band aids you like the best. I prefer the painless ones with a superhero on them.