I disliked him, but you have to admit he was a polymath: Producer/director/writer/impressario/performer/actor/broadcaster.
He brought political satire to the mainstream by devising TW3 and discovering David Frost. Remember, it was Frost who discovered Monty Python, so no Sherrin- no Python.
He promoted the musical Side By Side With Sondheim.
He was a film producer for many years- producing Up Pompeii, Virgin Soldiers and many more.