I didn't care for Alistair in Dragon Age until my third time playing the game when I was determined to have a fling with him (it's an achievement after all).  In order to get him to like you, you have to listen to him and talk to him often.  When I was nice to him and actually listened, I learned why he is the way he is: he's an orphan, a bastard child unwanted due to him being a threat to the rightful heir and whose mother died giving birth to him, which is why all his sister wants from him  is money.  Also, he saw Duncan as a father figure and he didn't have friends until  he became a Grey Warden, so all of his friends and his "father" died at Ostagar.  After all of this he's expected to save the world.  I understand why he leaves most of the decisions to my character--he's an emotional wreck and he knows his decision-making skills are not sharp. All he wants is to let you lead and to fight bad things.  That's his way of coping.  He's a damaged knight, and for a lot of us (me included) that was new; we're not used to complex, emotional heroes/knights in RPGs.  Alistair is like a lot of us, which is why I think many of us didn't like him.  If you play the game again, give him a chance....and all of Cailen's armor.