Whilst I agree that Countdown has never been the same since Richard Whiteley died, it is as much a part of Channel 4 as Coronation Street is of ITV, and I was pleased it continued. Des Lynam was OK, after a shaky start, but unlike Whiteley, he never gave me the impression that he was all that committed to Countdown, so I am not astonished to see him quit, but surprised it came quite so soon.
Channel 4 has also shown some great US dramas (The Sopranos, Six Feet Under, Hill Street Blues), produced some of it's own (recently, Green Wing, Shameless), and documentary series like Dispatches and Cutting Edge are always worth looking at. Jamie's School Dinners also came from C4, which has had a major impact in the UK, and I'm hooked on Deal Or No Deal! You also have Film4, which has produced some classic movies (Trainspotting, Withnail & I, Touching The Void, to name a few), so I can't agree that C4 only exists for Countdown.