There's no sequel?!

[Elbub]

The originally intended Monkey Island 3! I know that's cheating, as there have been three games since the second one, but they were led by different teams. A Ron Gilbert third installment would have been better...

In a similar vein, Dungeon Keeper 3! We can blame E.A. for this, like so many of the gaming world's ills. War for the Overworld is the spiritual successor, and a good game, but it just lacks... something that made the original games so special.