[tbw2]

If Romney is the Republican nominee, is it better to vote for Romney or not vote at all?
Is it better to have a RINO win or Obama win?

[Timaeus]

If Romney is the Republican nominee, is it better to vote for Romney or not vote at all?

Better not to cast a vote for president or write in your own candidate. A contributor who goes by the moniker aMorePerfectUnion posted this answer by way of a quote: "If we must have an enemy at the head of Government, let it be one whom we can oppose, and for whom we are not responsible, who will not involve our party in the disgrace of his foolish and bad measures."- Alexander Hamilton

Voting for every other Republican down-ticket is probably a good idea though, don't you think?