As there is thread drift already, I'd like to proffer 'Down The Line' as the funniest British comedy I've heard in a very long time. Again, something that seemed to pass most people by, even though there's a lot of big-ish comedy names attached.

It's a spoof of the likes of Talk Sport/Talk Radio (I think it's very specific to Ian Collins and Piers Hearnu, personally) with a lot of 'Fast Show' type names but a lot funnier than things like the Fast Show in my opinion.