My viewpoint is a bit different.
IMO there are *2* completely different types of "Favorite" and "Least Favorite" reactions to each party member (..without respect to actually being *useful* for the party). The Dog is an exception because the Dog doesn't "talk".
1. Is how they react to your character, and particularly how you choose certain actions for your character.
2. Is how they react to other party members.
For instance I can't stand Wynn's hen-pecking/second-guessing of my character, but she is absolutely the "tops" when it comes to interaction with other party members. She predictably "fights" with apostate mage Morrigan, but she is best with Ogren and Lelianna for dialog. (..and it even changes depending on who else is in the party at that time, even if they aren't "in" on the discussion.)
As far as their overall personality - each is purposefully flawed to act irrationally, with "blind-spots". When they do it's uncharacteristic for that companion while being completely within "character". (..again, the Dog is the exception - his personality is consistent.)
Party member irrational behavior triggers:
Alister: Responsibility for/to others.
Morrigan: Love.
Lelianna: Cruelty.
Sten: Child-like pursuits.
Wynn: Apostate Mages and Abominations. Even though she is one.
Zeveran: Romance.
Oghren: Women (particularly Branka).
Shale: Reliance.. oh, and pigeons.
(..note that she is the only character with an obvious and unavoidable irrational trigger.)
Conversely the party member's most basic motivation is:
Alister: Loyalty (..which is exactly the same as the dog.
)
Morrigan: Self-Interest.
Lelianna: Selflessness. (polar opposite to Morrigan..
)
Sten: Duty.
Wynn: Wisdom.
Zeveran: A lack of Loyalty (..the *near* polar opposite of Alister.) His attitude is beyond purely self-interest because he still does things that aren't entirely within his interests (..even beyond his irrational trigger) , and yet it isn't specifically "disloyal" because of a reasonable amount of self-interest in most situations that would otherwise be deemed "disloyal" (..in other words he doesn't go "out of his way" to actually be disloyal).
Oghren: Bullishness.
Shale: Self-Reliance.
One of the things I find most interesting about an RPG with good character interaction is that at least a few of the characters can be "changed" because of their time with your character.
For Dragon Age, a few of the characters could actually alter their personality - specifically targeting their "blind-spots", getting them to see their inconsistencies and actually make a change in their behavior because of it. Alister and Lelianna *can* fit this description, and Shale (ultimately) does fit this description. (..what I didn't like about it was the implementation, or specifically the "hardening" mechanism which was a little *too* "pat" and abrupt. Shale on the other-hand changed over time, not too much ..but enough.)
Oghren: understands his "blind-spot" but doesn't really do anything to alter his behavior.
Wynn: (similar to Oghren), occasionally questions her blind-spots, but does nothing differently.
(Hmm, I wonder if there isn't something of "can't teach an old dog new tricks" for Oghren and Wynn?)
Morrigan: dismisses her blind-spot.
Sten: (like Morrigan) also dismisses his blind-spot.
(.."if a tree falls in the forest but no one is there to hear it, does it make a sound?")
Zeveran: Not only understands his irrational behavior, but actually *revels* in it. In a circular way - it "feeds" his lack of loyalty.
(..strangely, he is the only "self-actualized" companion.)
From the above overall personality profiles for the companions, I *liked* Oghren the best. His "head-long" charges despite poor odds, his crass humor, and his *seemingly* simple nature that actually belied a "bedrock" of wisdom.
(.."everything is simple, except when it isn't.")
However, (perhaps oddly) I "identified" with both Alister and Morrigan. ..If you've ever looked at a Chinese "year of" animal cycle and looked at the descriptions for your year and the others, then perhaps it won't seem so odd that identified with both Alister and Morrigan ..for I was born in the year of the Dog.
