Darth Vader, according to the Visual Dictionary
From 1998 (before the prequels).
Once regarded as mad human wreckage, with the increasing favor of the Emperor Vader has risen in power and influence to become a much-feared military commander. Grand Moff Tarkin was once of the few who recognized Vader's capabilities in spite of his bizarre appearance and eccentric conduct, and as Tarkin's right-hand man Vader attained a new level of respect amongst the upper echelons of the Imperial military.