This one's actually kinda good!
the okcupid politics test
not sure if you have to be logged in or not, I don't think ya do. it's quick, easy, and the results are kinda interesting. Of particular note, they ask you at the end who you're voting for in the 2004 election (doesn't effect your score), and then on the chart, you can view where the major US political parties lay and then, click on the "election" button and it shows the people who say they will vote for either bush or kerry with little blue/red dots. It's damn amazing and makes a lot of sense the way it's aligned.
Oh, and I got the general score of "Libertarian" with 80% socially permissive and 68% economically permissive.