One of the very worst, Confederate General Braxton Bragg.
After the Union's wholesale retreat to Chattanooga after Chickamauga, Forrest and Polk implored Bragg to attack the disorganized Union force with a greatly superior Confederate army still bolstered by the presence of Longstreet's Corps from The Army of Northern Virginia. Bragg refused, and instead decided on a siege which was doomed from the start.
"Perhaps the ultimate cap to the Confederate experience of Chickamauga occurred later in the night of September 20. Polk reported to Bragg that the Federals had fled the field, and a pursuit was needed. According to an aide present, Bragg "could not be induced to look at it in that light, and refused to believe that we had won a victory."
If that wasn't bad enough, a Confederate soldier who had been captured, but escaped, was produced to corroborate the story of the retreating Federal army. Bragg still refused to believe. "Do you know what a retreat looks like?" he snapped at the soldier. Setting the stage for an unforgettable one-liner that was the talk of reunions for years, the Rebel fired back, "I ought to, General; I've been with you during your whole campaign." Bragg's reply was not captured for the record."
This was the exchange that resulted between Forrest and Bragg on Lookout Mountain:
"I have stood your meanness as long as I intend to. You have played the part of a damned scoundrel, and are a coward, and if you were any part of a man I would slap your jaws and force you to resent it.
"You have threatened to arrest me for not obeying you orders promptly. I dare you to do it, and I say that if you ever again try to interfere with me or cross my path, it will be at the peril of your life."
(This quote was told after the war by Forrest's chief surgeon, Dr. J. B. Cowan. Cowan was the only person besides Bragg and Forrest that heard this exchange. Afterwards, Cowan exclaimed to Forrest, "Well, you're in for it now." Forrest replied, "He'll never open his mouth. Unless you or I mention it, this will never be known.")
One of the best for his time: Benedict Arnold, prior to turning traitor. Led from the front, spent his own money to train and equip troops and won some pretty hairy battles. After being seriously wounded at Saratoga and having the credit for the victory stolen by
Gen Gates, then got shafted by Congress. Great combat general, but got buttraped by the politicians and turned traitor afterwards. Arnold saved our ass multiple times during the revolution. If he hadn't turned traitor he'd probably be one of our national heros, up there with George Washington
One of the worst of the time: Horatio Gates. Lost every battle he was in command for. Claimed credit for Saratoga while the real hero was in a hospital trying to keep doctors from cutting his leg off. Spent more time hanging out with congress then he did in the field. And was in a perpetual state of butthurt over Washington getting command of the Continental Army and spent the entire war trying to discredit
GW and get command.