Clockwise (1986)*, A Fish Called Wanda (1988), Fierce Creatures (1997)

Three starring vehicles for John Cleese, the former Monty Python writer-performer and for many the most important single living figure in British comedy (largely on account of Fawlty Towers, a surprisingly traditional but impressively controlled and often irresistibly funny BBC sitcom).

Of these three, it is the first, Clockwise, that trades most explicitly in the legacy of Fawlty; it is also by far the least-remembered and appreciated of them, perhaps because Cleese had no hand in the screenplay. Yet it seems to me by some measure the best; indeed, for the first fifty minutes or so it looks set to be a small post-Ealing classic of British social comedy, with Cleese's Brian Stimpson (basically Fawlty recast as a school headmaster) gradually losing his reason as he tries, against relentless obstacles, to get to a headmasters' conference in Norwich. 
Sadly, it trickles away to nothing in the final third of Michael Frayn's screenplay: regardless of his reputation, someone should have pressed a collaborator (or polisher) on him, ideally Cleese himself, who knows a thing or two about comic narrative momentum. 

A Fish Called Wanda proved an inexplicable smash hit at the time of its release, though I doubt many come back to it today with the same undimmed fondness retained for Fawlty. The Ealing heritage is here made explicit by the recruitment of Charles Crichton as director, but it's always struck me as very rudimentary stuff indeed, with few laughs and fewer surprises, and little value even as a time-passer thanks to its relentless cruelty and mean-spiritedness. 
The plot is an elaborate thing about unlikely robbers pulling off an unlikely heist, but any resemblance to The Lavender Hill Mob ends with the pedigree and the précis.

Fierce Creatures, a second trip to the well for the same players, proved as surprisingly difficult to launch as Wanda had been surprisingly successful: poor previews led to its withdrawal, and to extensive, almost certainly detrimental re-shooting with a new director. What finally emerged was generally conceded to have just missed the mark, with a weird premise about a huge American conglomerate buying a small British zoo and making it stock only ferocious animals. But while it is scarcely any more inventive or important than Wanda, it is, surely, a hundred times more likeable.