They've all been zany oxbridge stuff or based around one EXTRAORDINARY performer (from oxbridge) since big train.
Quite possibly true. Big Train was good, but before that and The League..., I'm thinking you might have to go all the way back to The Day Today for genuine quality.
Admittedly their sit-coms are usually very different in style from ours, but can anyone think why there never seem to be any sketch shows from the USA? I know they lapped up Python back in the day, and sadly Little Britain is being exported, but they don't seem to export anything sketch-based to us.