If he would have listened to Longstreet at Gettysburg, the south may have won the war.
While he was loved by his troops, he was a pretty poor general letting his ego cloud his judgment and by his own admission was responsible for the unnecessary death of thousands of his men at Gettysburg which was the turning point of the war.
Lee was clearly outsmarted by Meade at Gettysburg.
Meade deserves a lot of credit for outmaneuvering Lee in the days leading up to the battle.
Once battle was joined the Southern Army was effectively trapped into making a frontal assault.