QualiaSoup has some great videos, although many of them are in the excessively tired "trying to convince Christians that their religion isn't right" genre.
edit: Perhaps that's not the best name for the genre; it's more a kind of rational argumentation against ideas floating around the Christian memeosphere. But I'm still skeptical that it does very much good.
An interesting little Flash-like video on "openmindedness" by someone named QualiaSoup (hopefully ironically).
Does anyone know how much effort is required to produce this sort of video, perhaps from a script? We need at least another thousand of these.