Combat Flight Simulator 2 Movies
Microsoft's "Combat Flight Simulator 2" was very popular a few years back, and still enjoys a dedicated following of thousands of enthusiasts, because it featured a respectable flight model, reasonable mission editor, and the ability to build custom, simulated aircraft. Many, many simulated aircraft have been built by fans, and the best of them can still be downloaded from enthusiast websites. It's tricky to capture mission movies because CFS2 has no direct, built-in facility for that, but a few people have managed.