As Professor Proton, a spoof on Bill Nye the Science Guy (also on the show), Bob Newhart has been on The Big Bang Theory several times.
Sheldon always catches him off guard and he can’t get enough of Penny! Newhart even won an Emmy for the small role.
Astronaut Buzz Aldrin
Most people know that Buzz Aldrin is the second man to walk on the moon, but he’s also guest starred on The Big Bang Theory back in Season 6 of the show. His character loves telling everyone about his accomplishments and Raj hopes his repetition of the story will help Howard stop talking about his trip so much.
Star Trek Star George Takei
Star Trek’s George Takei plays a version of himself in one of Howard’s dream sequences. The romance scene first stars Bernadette, followed by Battlestar Galactica’s Katee Sackhoff when Takei surprisingly shows up to join in. In another scene, and various references, Leonard Nimoy has done voicework for the show.
Marvel Comic Creator Stan Lee
It’s likely that anyone who has ever seen a Marvel movie has seen a Stan Lee cameo, but he’s also been on The Big Bang Theory. On the show, Penny is trying to help Sheldon get the legend’s autograph, but when they show up uninvited, he ends up getting the autograph on a restraining order.
Star Trek’s Wil Wheaton
While he may not be the most well-known star of all the cameos, Wil Wheaton has become a regular on the series as Sheldon’s nemesis. Wheaton has appeared several times, playing a heightened version of himself.
Before Sheldon decided to drunkenly fight Wheaton, the child star broke up Leonard and Penny, but also ended up costing Sheldon and Raj a game of Mystic Warlords of Ka’ah, which would hurt Meemaw’s feelings…
Who is your favorite guest star on The Big Bang Theory?