Mayim Bialik, Johnny Galecki, and Jim Parsons in The Big Bang Theory (2007)

Laurie Metcalf in The Big Bang Theory (2007)

Jim Parsons in The Big Bang Theory (2007)

Kaley Cuoco and Jim Parsons in The Big Bang Theory (2007)

Mayim Bialik and Johnny Galecki in The Big Bang Theory (2007)

Mayim Bialik, Simon Helberg, and Jim Parsons in The Big Bang Theory (2007)

Mayim Bialik, Kaley Cuoco, Johnny Galecki, Simon Helberg, Kevin Sussman, Jim Parsons, and Kunal Nayyar in The Big Bang Theory (2007)

Mayim Bialik, Kaley Cuoco, Johnny Galecki, Simon Helberg, Jim Parsons, and Kunal Nayyar in The Big Bang Theory (2007)

Mayim Bialik and Kaley Cuoco in The Big Bang Theory (2007)

Mayim Bialik and Jim Parsons in The Big Bang Theory (2007)

Kaley Cuoco, Johnny Galecki, Simon Helberg, and Kunal Nayyar in The Big Bang Theory (2007)

George Takei, Simon Helberg, Katee Sackhoff, and Melissa Rauch in The Big Bang Theory (2007)

Simon Helberg and Katee Sackhoff in The Big Bang Theory (2007)

Bob Newhart in The Big Bang Theory (2007)

Christine Baranski in The Big Bang Theory (2007)

Mayim Bialik, Kaley Cuoco, Johnny Galecki, Simon Helberg, Jim Parsons, Melissa Rauch, and Kunal Nayyar in The Big Bang Theory (2007)

Jason Kravits, Kaley Cuoco, and Melissa Rauch in The Big Bang Theory (2007)

Wil Wheaton, Mayim Bialik, and Jim Parsons in The Big Bang Theory (2007)

Sean Astin, Mayim Bialik, Kal Penn, and Jim Parsons in The Big Bang Theory (2007)

Mayim Bialik, Kaley Cuoco, Johnny Galecki, and Jim Parsons in The Big Bang Theory (2007)

Mayim Bialik in The Big Bang Theory (2007)

Simon Helberg and Kurt Scholler in The Big Bang Theory (2007)

Kathy Bates and Jim Parsons in The Big Bang Theory (2007)

Johnny Galecki in The Big Bang Theory (2007)

Johnny Galecki and Kunal Nayyar in The Big Bang Theory (2007)

Kaley Cuoco and Johnny Galecki in The Big Bang Theory (2007)

Simon Helberg in The Big Bang Theory (2007)

Kunal Nayyar in The Big Bang Theory (2007)

Melissa Rauch in The Big Bang Theory (2007)