Watch Chuck Lorre's Admitted Failure: The Original Big Bang Theory Pilot
Here's your Big Bang Theory trivia of the day: Long before Kaley Cuoco joined the CBS sitcom as Leonard and Sheldon's ditzy neighbor Penny, Chuck Lorre shot a pilot with unknown Canadian actress/VJ Amanda Walsh as his female lead. Walsh and her character -- a street smart gal with a sensitive core -- were both scrapped by Lorre after CBS rejected the pilot. Now, thanks to the wonder of the internet, that original episode (that even Lorre said "sucked") is available for your viewing pleasure.
Note that this pilot, initially shot for the 2006-2007 television season, included a nerdy character Gilda (Iris Bahr) who would later be replaced by Sheldon and Leonard's friends Wolowitz (Simon Helberg) and Raj (Kunal Nayyar). Also, the original theme music (Thomas Dolby's "She Blinded Me With Science") was later switched out for an original Barenaked Ladies score. Two years ago, when an interviewer suggested that fans might be interested in seeing the original pilot, Lorre responded, "Wow that would be something, we will see. Show your failures..."