Presuming your vote wasn't thrown away if you voted for a third party (via proportional representation or a run-off or something similar) would you stay in the current party you are in or would you join a different one? I'll list the current two major US parties and the three major third parties and try to summarize their views very briefly in very broad terms.
Constitution Party (very socially conservative, religious, small government/low taxes, economically and militarily isolationist)
Democratic Party (Morderately socially liberal, economically conservative, large central government, higher taxes for social welfare and healthcare programs, moderately isolationist)
Green Party (Socially liberal, economically socialist, strong wealth redistribution programs w/ universal healthcare, strict enviromental protections, strong local government, disarmament policy)
Libertarian Party (Economically liberal, socially liberal (individualism), small government, very low taxes, non-interventionist)
Republican Party (Socially conservative, economically moderately liberal, traditional values platform, moderate government size, moderate/low taxes, interventionist)