I've been a fan of Penn and Teller for a long time. They are great comedians and magicians. They are also skeptic in the tradition of Houdini and the Amazing Randi.
What the confront is stupidness, flimflam, and humbug of American (and world) culture. They aren't republican and they aren't democrats. They instead leans toward a lesser known party that favors people over gov't, Libertarianism. As a result much of what they confront deals with gov't pushing stupid agendas and scheisters preying on the uninformed. I myself lean very much to libertarian views and find myself agreeing with much of what Penn and Teller say. There are some points I very much don't agree with (id say their stance of religion in general is a bit driven soley by their being athiests. In this they push agenda more than inform) but most of what they say is very well reasoned and told in a humorful way.