Most recent example that comes to my mind is Mario + Rabbids which many thought it was going to be another cheap lazy cashgrab like most of the Rabbids games and also being a bizarro concept that couldn't possibly work well, right?
What we got in the end was a well-designed fun x-com-like strategy game with a lot of heart and soul poured in by the devs. Even the Rabbids in the game are more charming than annoying. That and it did have some legitimately funny moments.
Great game, recommend it if you have a Switch.