I have recently played my second warbands game against a chaos friend of mine. He has quit a lot to choose from. In this battle, he went with a bunch of chaos knights versus my modest DE force.
Now, My force was comprised of a noble wearing heavy armor equiped with the crimson death, 8 warriors with spears, shields and full command, and two units of four warriors with RxBs and shields. I also had the unyielding, unfailing, Reaper Bolt Thrower of Doom.
He had a unit of six chosen chaos knights with a unit champion and three regular chaos knights.

My deployment was the noble in the unit of 8 spearmen at the center, the reaper on a hill behind them and RxB men on the flanks of the warriors. The chaos forces deployed in a line, about 18 inches away.

I got first turn, and decided not to move forrward. My shooting failed to kill a single warrior. He decided to march forward, and he closed to a distance of 4".

The second turn, I thought about the possibility of a chaos knight charge, and I decided that it would be less devastating to my warriors if they charged. My left unit of RxB men charged along with my spears. The Noble did not get to attack, and out of six Chaos Knights, one died. They then killed five spearmen, and two RxB persons. I managed to not break. My shooting accomplished nothing, again.

His turn, rather than charging my unengaged crossbow unit, he flanked my spearmen and charged the noble. The noble managed to survive, somehow. None of my nits broke that turn.

My turn again, and I decided to flank his three knights with my crossbowmen. They failed to do anything, and the noble went down. His Chosen suffered a casualty from the two surviving crossbowmen, and inflicted a few casualties to the spearmen.

Things were not looking good for me. My RxB fought and managed to avoid casualty. My other men still managed to survive. During his turn, he manage to kill the last two RxB men with his regular knights. My spearmen managed to die, but the RxB men held their ground.

My turn, and my RxB took out the two knights that remained of the regular knight unit. Over his and my turn, the remaining RxBs that had bravely held their ground died.

I then, assuming I would be destroyed, managed to kill three of his knights with the Reaper. Then, he charged, killed one man and retreated. In my turn, that bolt thrower dispensed of him in a hil of arrows.

Now, in total, the that bolt thrower has taken out eight chosen chaos knights and has never been knocked out.