There's a few classics here!
The Damien Nettles one on bbc 3 a few years ago was good, I always got the impression that its one of those where they know with 99% certainty who did it (the drug dealer) but just cant pin it on him, and he's dead.
Holiday showdown was an absolute classic, one that sticks out in my mind is one with a quite hip mixed race family, the mum of whom is originally from Jamaica, and they have to go to Dollywood with some bloody awful woman who is a massive Dolly Parton fan. The jamaican family are bored rigid and piss about all day and the Dolly parton woman absolutely blows her top at them, iirc the kick off all takes place at a green screen attraction where you get digitally inserted into a dolly parton video which just made it even funnier. Did anyone ever see it? I've never found the full episode online.
Dogging Tales and My Reborn Baby are other great ones, I\ve heard sooo many people talk about the porn star buying the island thing on CHannel 4 but I don't think I saw it at the time i'd love to watch it now.