Now really should be pigeon-holed as a classic comedy sit com, as much as Only Fools and Horses, Fawlty Towers, Blackadder, Father Ted, Spaced etc. It is constantly humourous and frequently hilarious. Dylan Moran is a revelation as Bernard Black, basically just playing a drunk Irishman for the whole 3 series - but he does it soooo well. Bill Bailey manages to squeeze some of his off-the-wall comedy into the proceedings (especially good is what happens to Manny when he reaches 88 degrees). And Tamsin Grieg is the perfect askew moral (or morally askew) centre of logic, her inhibitions leading to much of the comedy surrounding Fran.
There are no real stand-out episodes really, with the possible exception of 'The Grapes of Wrath', but it's the individual scenes that stand out: Bernard offering Manny a job, although Manny is sitting on the table behind him; the 'cleaner' sliding into shot below a kneeling Bernard; Manny's genius piano 'spooning', 'Luxury Pie' and Bernard's Belly Savelas. So much to chuckle at and so much to revisit.