Topless Robot has counted down what they feel are the ten most painful video game cancellations, with Obsidian's Aliens: Crucible and EA's The Lord of the Rings: The White Council both scoring mentions. They've also embedded that Aliens: Crucible gameplay footage we saw back in January, just in case you missed it the first time.
These two are getting lumped together because we know roughly the same amount about both. Each is a based on a fan-favorite movie series, but both were canceled before too much information was released about either game. The White Council was described as open-world RPG in the style of The Elder Scrolls IV: Oblivion or Fallout 3. The Aliens RPG, based on the very, very dark footage that leaked online, played more like Mass Effect and was nearly complete when it was canceled by Sega, according to the head of developer Obsidian. Thanks a lot for that, Sega!
Those two are definitely up there, but the cancellations I had the toughest time with were Van Buren and Jefferson (Fallout 3 and Baldur's Gate III). Such potential, wasted.