I have recently fallen in love with empire knights.
In a game against Wood Elves, I let my 'Nilla knights get flanked by ten wardancers to protect a large unit of swordsmen. Giving the knights up for lost, I moved the battle away from that combat, but to my and my opponent's surprise, three turns later, having sustained no casualties, the knights broke and chased down the wardancers before returning to the battle and rear charging a pesky unit of glade guard!
Has anyone else had this miraculous experience with knights or any other unit?