While picking the best Democrat to vote for in the Presidential primary is a worthy task, let us not forget we must also decide who we want the Republics to nominate. Of course there are two main criteria in this selection process. First, who is most likely not to foul up the Country and two, who is most likely to get their ass beat come the General Election. These factors may not always line up. My personal favorite Sam Brownback, (Gone now, Boo-Hoo) was sure to beaten in a general election, but would be a catastrophic social issue-wise if he were ever elected. Mike Huckabee is far scarier, because he brings the same regressive social policy in a much friendlier, more electable package.
But among the top tier, A strong case emerges for Romney. Basically, he was a moderate technocrat like 7 minuets ago, and is such a transparent phony that he could easily switch back and pursue moderate policies once in office. Plus he doesn't seem as committed to staying in Iraq and bombing Iran as the other guys. So Romney is the most likely closet moderate. I'm not saying that's likely and he could easily remain a right wing tool but hey we are picking the least bad option here. Rudy Giuliani on the other hand, would be a real danger to the Republic.
Plus, electability. While Rudy! has the 9/11 halo and general moderate appeal, Mitt!? has no special appeal beyond that of any generic Republican. And generic Republicans right now are doing terrible.
So Romney is the man. For both the not screwing the Country and beatablitiy factors.