Those Magnificent Men in Their Flying Machines
The director of which, Ken Annakin, passed away yesterday (which imdb hasn't noticed yet).
My list:
The Way to the Stars - the gripping story of the ficticious RAF aerodrome at "Halfpenny Field" the only film which concentrates on both the RAF and USAAF, with Michael Redgrave, John Mills, and (the often present in British made films) Bonar Colleano in his often reprised role as the loud New Yorker! Great film, in a typically understated film.
The Dambusters. Micheal Redgrave again! Awesome film, and an excellent example of how to tell a heroic story without bending the truth, or altering history altogether. Early appearance from Inspector Wexford too.

Mag Men - see above. Aviation meets comedy at its best. Aside from that, it produced some excellent reproduction pre WWI aircraft, some of which still fly today.
Battle of Britain. Epic. Aerial filming possibly only better by the film below. Did wonders for the future of warbirds (thanks to Hamish Mahaddie, ironically an RAF bomber pilot in WWII). Great cast, and a super soundtrack by William Walton (which they then replaced with a very good one, but slighly repetitive one by Ron Goodwin) - due to the wonders of DVD you can now watch it with either.
Memphis Belle - like the Dambusters in the way it told it's story, although "fictionalised" the elements of Memphis Belle story, it didn't do it to the ridiculous extent of other Hollywood offerings (Pearl Harbo(u)r, etc) - which maybe explains why it wasn't as successful as it could have been). Great casting too. Aerial shots to die for, and good that they spent the extra money to film it in the UK with authentic scenery.