My .02 on this volatile subject:
I am loathe to tell other people how they should vote, but if you tell me that you will stay home if your preferred candidate doesn't get the nomination, I reserve the right to think that you're a self-centered idiot.
I don't think Obama is the savior of the Democratic Party, or that Clinton is the only one who can defeat McCain. I don't expect either one of the them to be perfect; if I had my druthers, we would have a truly progressive candidate instead of two mushy centrists to choose between. But if you can't see that either of them is better than the alternative, you need more than the services of a good opthalmologist - you need to ignore the past 8 years, pretend that the 2000 election never happened, and think so highly of your own personal take on the political situation that you can't fathom that maybe you don't have all the answers.