This is the key point. If you don't like Obama but vote for anyone other that Romney, YOU'RE VOTING FOR OBAMA! That's one vote away from defeating Obama.
Romney is is the the ONLY chance we have against Obama right now, like it or not. Sorry, but that's you're only choice for a winner against Obama. You can make a "protest" vote for a libertarian, etc., if you wish but in the end it will be a vote for Obama.
You can live with that if you choose to vote Obama (or libertarian, or whatever). I won't have to.