Channel 4 is arguably the most innovative station in the UK, shying away from mainstream TV popularised by ITV, displaying shows which take more risks than the BBC is prepared to. It is seen as being edgy whilst not being foolishly over-the-top.
Channel 4 is one of three commercial terrestrial television stations in the UK, coupled with ITV and Channel 5, and was set up in 1982 with the manifesto of providing information, entertainment and education. Programming started at 16.45GMT on 2 November, 1982, with the quiz Countdown the first show to be aired (Countdown is still one of the most popular C4 shows today). It outputs quality youth and entertainment television, so much so that a digital spin-off channel, E4 was created to solely display these specialist areas. It also has a large division in film funding known as FilmFour, which again has it's own digital channel screening FilmFour productions for the first time on television. Of course, Channel 4 also screens documentaries (some risque, such as "The Truth About Gay Sex") and other educational genres. It employs ITN for its news coverage.
Channel 4 has screened famous shows such as Friends, Frasier, Father Ted, Scrapheap Challenge, Spaced, Big Brother UK, So Graham Norton, Time Team, Da Ali G Show. Channel 4 has also screened infamous shows, most notably Brass Eye by Christopher Morris. This show attracted a lot of attention as it was a docucomedy on paedophilia and seen as inappropriate by many portions of British society. It won comedy awards regardless.
The best sum up of Channel 4's reputation I heard was during a conference on language when the speaker was discussing context, comparing a programme to Channel 5's reputation of trashy shows (Ultimate Crash Tests, for example):
Speaker: You may have seen Naked Jungle on Channel 5, a game show done entirely naked. The next day, everyone said it was the lowest of the low, the worst television programme ever. If it had been screened on Channel 4, however, it would probably have been heralded as a wonderfully satirical piece of programming.