It isn't sequels that are the problem, it's making sequels to games that should have been left to die. Gears of War got old halfway through the first one. I spent most of my time waiting for it to end because it was so crushingly linear and repetitive.

Games that have a good story and varied gameplay can do well, they're just not made by Epic.

Half Life 2 had a good story, puzzles, vehicles and a great physics engine and was consistently engaging. Uncharted 2 had the familiar but varied gameplay, a great control scheme, a likeable cast and a whole new story.