Take two physicist brainiacs/best friends, Leonard (Johnny Galecki) and Sheldon (Jim Parsons), add gorgeous girl-next-door Penny (Kaley Cuoco), and you've got an equilateral triangle of chemistry, combustion and quantum comedy. Multiply the laughs with techie colleagues Raj and Howard, and The Complete Seasons One through Four of The Big Bang Theory equals some of the most addictive television ever. Watch the Big Bang gangs romantic universe expand in the award-winning genius comedy that delivers funny to the infinite degree.