Fallout 3's ending was horrid. You didn't really do much at all during the last fight, and the end scenes had little to no effort put into it. It's just some guy talking over a few stills, adn the variations of the ending aren't really that unique.

Dragon Age Origin's fight against the Archfiend was dull. It was just some dragon and a crap ton of Darkspawn. It wasn't even that cool of a dragon, so it was very underwhelming to fight it.