I've just had a look and we haven't talked about this yet, which is a shame because I think it's a slightly neglected classic. Michael Crawford's performance as Frank Spencer was genius, and the stunts he did were up there with Buster Keaton's.
And although the plots were never that great, it's one of the few shows that has the ability to reduce me to tears of laughter (the only other show to do this is Fawlty Towers). It also contains a style of comedy (physical, slapstick) that isn't attempted much in the modern sitcom, if ever. And they only made about twenty episodes, so they never outstayed their welcome.