Sir Lancelot is awesome by being the only knight (including King Arthur himself) able to get past the guardian of the bridge and crossing it safely, not by outsmarting or tricking the guardian, but simply by answering all of his questions honestly!
The music playing when the wooden boat takes King Arthur and Sir Bedevere to the Castle of Aaaarggh. You feel a sense of satisfaction for them as they've completed their quest. Almost brings a tear into your eyes. At least until the humor sets in.
King Arthur: Our quest is at an end! God be praised! (he and Sir Bedevere bow) Almighty God, we thank Thee that Thou hast vouchsafed to us the most holy- (a sheep is flung at them) JESUS CHRIST!!