To add to your inefficient list: DUXFORD. Unless they've had a 'sense' injection since I last visited, that is. It took me an hour and a quarter by the time I'd waited for the bowser to turn up, then had to walk to the Museum entrance to pay. Ludicrous. Won't go there again, even though it's my local field.
As for efficient, the best ones IMHO are the ones who will gladly do rotors running refuels. Sywell (if you call them before you arrive, no problem), White Waltham and Wycombe. Any others out there? I'm personally happy to pay a couple of pence more to save the shutdown/restart hassle if all I want is jet fuel.
Oxford is a bit painful, North Weald great, even though you need to shut down at both.