Until Fred enters the race, he is, by definition, not electable at all. One needs to be on the ballot.
But, in the spirit of your question: I'm at the stage where I am eliminating primary candidates, not endorsing them. So far, I have eliminated Giuliani, McCain, and Paul, for various reasons. Of those in the race, I like Hunter's record best, and Romney's stated policy ideas best.
In my comment I asked “who in your opinion is both conservative and electable based on past behavior”
Can you really consider Mitt conservative based on past behavior? Past behavior = words and deeds” Don’t get me wrong, I like Romney but his conservative bonafides are deeply troubling.
I also like Hunter a lot but unfortunately he is eminently unelectable.