Prop 8: The Musical
The brilliant Marc Shaiman wrote a musical, and a metric fuckton of stars showed up to film it (video below). This was directed and staged by Adam Shankman, and produced by Adam, Marc, and Mike Farah. Starring John C. Reilly, Jack Black, Neil Patrick Harris, Maya Rudolph, Kathy Najimy, Margaret Cho, Andy Richter, Jordan Ballard, Allison Janney, Rashida Jones, Lake Bell, Sarah Chalke, and a bunch more.
If that video isn’t working, go to Funny or Die to watch the clip.