Name: Charlie Sheen
Appears in: "The Griffin Equivalency" (2 × 04)
The role: himself
Biography in brief: Charlie Sheen is an American actor. He won a Golden Globe and was nominated for Emmy Awards. Among his most famous "Scary Movie 3", "Platoon" and "Two and a Half Men."
Name: Sara Rue
Appears in: "The Lizard-Spock Expansion" (2 × 08), "The White Asparagus Triangulation" (2 × 09), "The Vartabedian Conundrum" (2 × 10)
In his role as Stephanie Barnett
Biography in Brief: Sara Rue is an American actress. Among his most famous works are "Less Than Perfect," "Popular" and "Will & Grace."
Name: Michael Trucco
Appears in: "The Bath Item Gift Hypothesis" (2 × 11)
In his role as Dr. David Underhill
Biography in brief: Michael Trucco is an American actor. Among his most famous roles include Samuel Anders ("Battlestar Galactica") and Lee Cooper ("One Tree Hill").
Name: Summer Glau
Appears in: "The Terminator Decoupling" (2 × 17)
The role: herself
Biography in brief: Summer Glau is an American actress. She is known for playing the role of River Tam in the series "Firefly" and the role of Cameron in the series "Terminator: The Sarah Connor Chronicles." He was also a member of the cast of the series "Dollhouse."
Name: George Smoot
Appears in: "The Terminator Decoupling" (2 × 17)
The role: himself
Biography in brief: George Smoot is an astrophysicist and cosmologist U.S.. He won the Nobel Prize for physics in 2006, shared with John C. Mather for discovering anisotropies in the black-body cosmic background radiation by COBE (Cosmic Background Explorer). Their findings have strengthened the theory of the Big Bang.
Name: Wil Wheaton
Appears in: "The Creepy Candy Coating Corollary" (3 × 05), "The Wheaton Recurrence" (3 × 19) and "The 21-Second Excitation" (4 × 08).
The role: himself
Biography in brief: Wil Wheaton is an American actor. Among his most famous works include "Star Trek: The Next Generation" and "Stand By Me - I remember one summer."
Name: Katee Sackhoff
Appears in: "The Vengeance Formulation" (3 × 09), "The Hot Troll Deviation" (4 × 04)
The role: herself
Biography in brief: Katee Sackhoff is an 'actress. Among his most famous works are "24" and "Battlestar Galactica", in which he played the role of Captain Kara "Starbuck" Thrace, which enabled her to win a Saturn Award for Best Supporting Actress in a Television Series.
Name: Danica Mckellar
Appears in: "The Psychic Vortex" (3 × 12)
In the role of: Abby
Biography in brief: Danica Mae McKellar is an actress and American mathematician (the Chayes-McKellar's theorem same-Wynn) known for playing Winnie Cooper on "The Wonder Years" and have written two bestsellers' Math Does not Suck "and" Kiss My Math, "which helps young people to approach the study of mathematics. She graduated with honors in mathematics from UCLA.
Name: Stan Lee
Appears in: "The Excelsior Acquisition" (3 × 16)
The role: himself
Biography in brief: Stan Lee is a well-known comic book writer who has created iconic characters such as Spider-Man, the Fantastic Four, Iron Man, Daredevil and the X-Men.
Name: Judy Greer
Appears in: "The Plimpton Stimulation" (3 × 21)
In his role as Dr. Elizabeth Plimpton
Biography in brief: Judy Greer is an 'actress, known for his roles in Three Kings, 30 years later and 27 Dresses.
Name: Mayim Bialik
Appears in: "The Lunar Excitation" (3 × 23), "The Robotic Manipulation" (4 × 01), "The Zazzy Substitution" (4 × 03)
In the role of Amy Fowler
Biography in brief: Mayim Bialik is an American actress, known to audiences for his character in the television series Blossom same name.
Name: Steve Wozniak
Appears in: "The Cruciferous Vegetable Amplification" (4 × 02)
The role: Himself
Biography in brief: It is known as a proponent of the personal computer revolution. Although its contribution has been mainly directed towards the development of technologies and the resolution of technical problems, his familiarity with electronics and his almost legendary ability to reduce complexity and costs of electronic components have made him one of the figures best known in the computing world. In fact it was he who designed the Apple I, the first personal computer ready for use.
Name: George Takei
Appears in: "The Hot Troll Deviation" (4 × 04)
The role: Himself
Biography in brief: George Takei Hosato (Los Angeles, April 20, 1937) is an American actor of Japanese descent, which mainly owes his celebrity to the role in the TV series Star Trek, in which he played the helmsman Hikaru Sulu on the starship USS Enterprise.
Name: Eliza Dushku
Appears in: "The Apology Insufficiency" (4 × 07)
The role: Special Agent Page
Biography in brief: Elizabeth Patricia Dushku (Watertown, December 30, 1980) is an actress and voice actress United States. Among his most famous works include Bring It On, Buffy, Angel, Tru Calling and Dollhouse
Name: Keith Carradine
Appears in: "The Boyfriend Complexity" (4 × 09)
In the role of: Penny's Dad
Biography in brief: Keith Carradine (San Mateo, August 8, 1949) is an American actor. Among his most famous works include Dexter, Criminal Minds, and Nashville.
Name: Rick Fox
Appears in: "The Love Car Displacement" (4 × 13)
The role: Former boyfriend Bernadette
Biography in brief: Ulrich Alexander "Rick" Fox (Toronto, July 24, 1969) is a former basketball player and Canadian actor. Before turning to acting was a professional NBA and wore tunics of the prestigious Los Angeles Lakers and Boston Celtics. As an actor he starred in: Ugly Betty, One Tree Hill and He Got Game.
Name: Jessica Walter
Appears in: "The Benefactor Factor" (4 × 15)
In the role of: Wealthy Widow
Biography in brief: Jessica Walter (Brooklyn, January 31, 1941) is an American actress. It was co-star of the television series Arrested Development - Arrested Development (2003 - 2006), and currently plays in the 90210.
Name: Jessica Walter
Appears in: "The Benefactor Factor" (4 × 15)
In the role of: Wealthy Widow
Biography in brief: Charles Joshua Malina is an American actor. Among his most famous works include The West Wing, Terminator: The Sarah Connor Chronicles and Sports Night.
