SuperHornet, the F-18D and F-18E, was great.

Basically the navy pretended to update the Hornet (F-18A, F-18B, F-18C) but actually built a completely new plane. Clearly it isn't the same, because the airframe is dramatically larger. There is a tiny bit of stealth (nothing fancy) but otherwise it looks like the Hornet... except way larger.

It was designed very quickly and cheaply. That was the requirement, and it was met. The whole project was sort of an open secret, pretending to be a revision of the Hornet while actually being an entirely new aircraft. This seems to have evaded lots of bureaucracy.