Simsville.
It was to be a cross between SimCity and The Sims. I was really anticipating that. Then however, doom struck, and EA finally cracked down on them after having bought Maxis a couple years before and the game got cancelled. I already hated EA beforehand because of numerous other things, but that was the last drop that would initiate my lifelong EA boycot. I only still got SimCity 4 afterwards (EA didn't get it's dirty handsui on that franchise yet so it was luckily still unspoiled, but we all know what happened when they eventually did) and LotR Return of the King as a gift. The last EA game to ever enter my household.
Otherwise, to name something more well known, Star Wars Knights of the Old Republic 3, even though that was never formally announced. It was an amazing series, and rumours were there regarding a third and final installment being in development after the second game left the story wide open, but it never happened. I was saddened by that, and left especially sour when they eventually did reveal another game taking place in the same universe, but in my most hated genre, spearheaded, of course, by EA.