Spoilsport ;) Just think, it could have been Jacob and his Nemesis *blinks innocently*

Scenario.... hmmm....
What if Jack didn't operate on Ben.
What if Sawyer's parents never died.
What if Driveshaft's career really did take off.
What if Jin refused to do what Mr Paik told him.

Or if you want things a little simpler.
What if Shannon didn't speak French when they listened to the recording.
What if Jack refused to let Sayid torture Sawyer for the inhalers.
What if Locke still needed the wheelchair.

Um... I shall go have a longer think if you need more inspiration.