That movie is Sky Captain and the World of Tomorrow.
I absolutely loved it. In fact, I just got back from seeing it again, and I am still giddy. The spectacle of such a gloriously nostalgic, pulpy future-past (instead of "back to the future", perhaps we're going "onward to the past") with such wit and charm, such affection and respect for all its cinematic forefathers, and such pure joie de vivre is unheard of in the cynical world of film. And it is a deeply enjoyable, and yes, a deeply moving thing.
Perhaps I'm sentimental. But deep feeling is appropriate when we are dealing with the sublime, and I mean it absolutely and without reservation when I say that Sky Captain is, plain and simple, a thing of beauty. I think of all the old, bad science fiction movies that have become a part of me over time, for which I have such love, and I think further of the stories behind them. Perhaps you've seen Tim Burton's marvelous Ed Wood, about the life and dreams and burdens of its namesake director. Wood is pretty much universally panned as the worst director of all time, and yes, he really was awful. But despite the overwrought writing, the wooden acting, the dismal direction, the nonexistent budgets, a few of his works somehow shine.
Bride of the Monster showed me the archetypal mad scientist that I hadn't even known was exactly my pure mental conception of the same. And who among us has not, in moments of desperation, felt the indescribable anger and frustration of the alien Eros in Plan 9 from Outer Space: "You see? You see? Your stupid minds! Stupid! Stupid!" And for all his futile cinematic exertions, Ed Wood accomplished this, illustrated so beautifully in Tim Burton's film: he gave friendship and respect and purpose to an ailing Bela Lugosi in the twilight of his life. Perhaps that is reason enough for all the lousy movies.