10. Richard Dawkins
Many scientists have appeared on the show as themselves, including Neil deGrasse Tyson, Brian Greene, George Smoot, and most notably Stephen Hawking. If you were to ask me whether there were any other scientists who deserved an appearance, Dawkins would be the clear choice. True, the others work in the same fields as the guys on the show, but Dawkins' work in evolutionary biology is not to be discounted. Perhaps he could interact with Amy or Bernadette at their labs since they study neuroscience and microbiology respectively. A scientist of Dawkins' caliber deserves a spot to shine on a show that praises scientific achievement. However, if you really wanted to go for comedic effect, you'd need to highlight his views on religion. Dawkins is a noted atheist, and it would make sense if Sheldon were to see him give talk at a local bookstore or library. Why Sheldon you ask? Well, what would happen if this talk coincided with a visit from his deeply religious Southern mother? Since Sheldon has often found his mother's religious beliefs the antithesis of his scientific views, it would make sense if he brought her along to try to change her way of thinking Naturally, though, she would do as much as possible to disrupt Dawkins' talk. I'll leave the rest to your imagination.