Games that were too good for their own good.

[Bofferbrauer2]

Wizardry 8. The Swan song of classic cRPGs - and Sir-Tech had to sell adspace in the game just to get the game finished (they had to cut some sidequests and one dungeon along the way) and out and folded directly afterwards.

Also, Super Metroid. After all, the only reason why the N64 doesn't have any Metroid game is that nobody had the confidence to follow up on that game, it was just way too much of a tough act to follow.