1 Vader: Don't be too proud of this technological terror you've constructed. The ability to destroy a planet is insignificant next to the power of the Force.
2 Motti: Don't try to frighten us with your sorcerer's ways, Lord Vader.
3 Motti: Your sad devotion to that ancient religion has not helped you conjure up the stolen data tapes, or given you clairvoyance enough to find the Rebels' hidden fort...
4 Vader: Hmmm... Actually, that's a good point.

2012-01-05 Rerun commentary: In the movies, Vader really couldn't take honest constructive criticism, could he?

Imagine how things would have turned out if he'd just listened to people, taken their advice on board, and tried harder to be more open to alternative points of view.