I'm interested to see you put Thrawn below Pellaeon. Sure, Pellaeon comes out top on Service Record (70+ years in various navies) and possibly Legacy (peace between IR and NR, leading the IR through the Vong War, his role in the Second GCW, etc), but i wouldn't say he was particularly successful (he did retreat alot and lost the campaign that led to the Pellaeon-Gavrisom treaty) or terrifying. The New Republic was far more frightened of Thrawn than Pellaeon, Thrawn frequently demonstrated his versatility in utilizing different strategies and tactics (often leading him to outstanding victories) and is the only commander that i know of to have
their own simulation.
Anyhow. Like i did for the starfighter thread, im just going to pick someone i think comes top in each category:
Fear Factor: Darth Vader. Strictly speaking he wasn't part of the standard command chain, but he definitely inspired fear in his underlings and opponents.
Success Rate: Admiral Ackbar. He took a fledgling and disorganised rebel fleet and managed to turn it into a military machine capable of standing up to the Empire. He led the New Republic through countless campaigns and battles over the course of twenty years.
Service Record: Admiral Pellaeon. As i mentioned above, he served over 70 years in uniform through the Old Republic, Empire, Imperial Remnants and through, the Vong invasion, in the GFFA.
Versatility: Admiral Thrawn. Again as above. Excellent strategist able to identify and make use of his opponents weaknesses.
Legacy: Admiral Ackbar (again). He devised the strategy/trap that took the GFFA into the final stretch of the Vong War.
Honourable mentions: Wedge "so good he couldn't fail when he tried to" Antilles, Nek Bwua'tu (consistently beat the Thrawn Simulator). Probably many others i could mention here, but they've slipped my mind.