I was reminded of this a few days ago. It's a clip from Peter Kay's Britain's got the Pop Factor... and Possibly a New Celebrity Jesus Christ Soapstar Superstar Strictly on Ice, which is a genius parody of all the reality shows we know and love... or hate.
Part of its success was down to the attention to detail, with lots of nuanced observational comedy. Another factor is the participation of real-life reality TV stars - it's "presented" by Cat Deeley who plys her trade on So You Think You Can Dance in the States (and also the UK version) and judges included Dr Fox and Pete Waterman, former stars of Pop Idol. A host of guest stars also appeared including - somewhat incredibly - Sir Paul McCartney.
But the main element is Kay's creation, Geraldine. Partly based on Pop Idol winner Michelle McManus, Geraldine has a cracking back story - she used to be a man - and a surprisingly good singing voice. The winner's song - called "The Winner's Song" - is a pastiche of the type of song typical of such shows. Co-written by Gary Barlow, it was Kay's singing voice while recording it which inspired him to play a woman.
If you've never seen it, the DVD is available and I thoroughly recommend it. Here's a clip of Kay as his alter-ego, singing an unlikely medley of songs: