The Internet Skeptic: Global Warming Fails the Stink Test series.
My suggestion is to scan through the listed videos and select those that are hosted at Google (picture size and resulting resolution will be much larger and better). If you have at least version Flash9, you could alternatively use Hypernarrative's (Real) FullScreen YouTube & Google Video applet.
As the authors of the videos recommend, its highly suggested to view the Global Warming: Myth or Reality Presentation (runtime 2 hours 4 minutes). This video does an in depth, detailed investigation of the fundemental science underlaying the conclusion that anthropogenic sources of CO2 are the cause of global warming. Its produced by the "Committee of Concerned Scientists"