I think the makers of Spitfire Ace really deserve a lot of credit, on the basis of programmes 1 & 2. Given the Comet programme - which ended up with C4 having to apologise, when the Broadcasting Standards Commission found against the TV company - we might not have expected much: instead we get the real Battle of Britain heroes telling their story at length, in the manner of television documentaries from the 1960s and 1970s (what you might call the 'concentration span and credit-with-intelligence era of television').
Plus, of course, the bonus of cockpit cameras and first-rate sound.
AND the PPL won through! (Here, I must admit to an unashamed bias.)