I'm well aware of the arguments for and against Loghain. Instead of entering a "discussion" I will simply say what my decision was at the Landsmeet and explain my reasoning.
To start off I need to explain that every choice I make in the game is based on several things.
1. My character's origin. (i.e. Human Noble vs Dalish Elf)
2. My character's class. (i.e. Warrior vs Rogue)
3. My character's race.
4. My character's religious convictions including the likelihood of whether or not they would even have any. (i.e. Higher caste dwarfs worshipping the "Stone" vs casteless dwarfs with no feasible or legal means to improve their lives)
5. Actions and words taken in the game by myself or others.
6. What my character could feasibly know AT THAT TIME.
7. My own personality and thought processes that take into factor all of the above.
My character is Aaeden Cousland, human noble warrior. This character has been raised being instilled with the importance of duty, honor, and justice. He knows the importance of power and that it is used to protect and help. Misuse or abuse of that power has serious consequences. His father is kind and helps those less fortunate even members of groups who are considered less than citizens (and to others less than human). He has grown up surrounded by love from all his family and loves them greatly in return. He has also grown up with belief in the Maker, Andraste, as well as traditional beliefs concerning mages. He knows the history of his family including that his family fought against the king of Ferelden at one point in history and were forgiven. He is aware of the history of the war between his country and Orlais. Like his father he does not fear or hate them but like his fellow Fereldens he does not entirely trust them and is wary of them.
*NOTE: The bit about responsibility and abuse of power is based on your first mission or rather afterwards. After dealing with the rodents and you talk to the gripey old woman you find out she was your nanny. She proceeds to tell you a story she constantly told you as a child. The story is about a mabari hound that was chosen to be the companion to the son of a. Because of this privelage he started treating his fellow hounds and their owners poorly. The years went by and the arrogance and cruelty of the hound increased to a point that the chieftan decided to choose a different hound for his son. Enraged by this decision, the hound attacks the chieftan and bites him. The entire tribe and even his fellow hounds turn on him and kill him. This teaches my character that being a leader means that the way you weild your power and abilities affects everyone. You need power and competence but it must be tempered with empathy and compassion.
Now my decision: Loghain is killed by me. Allistair and Anora rule together.
REASONS:
1.) Allistair is by blood the rightful heir to the throne. As a noble this would be important to me. Although I understand his shortcomings he has a level of sympathy, empathy, and compassion that is necessary for a leader. Anora has what Allistair lacks which is experience, decisiveness, and the ability to remove herself emotionally from a situation. The two of them together are better than apart. HE keeps her from becoming indifferent and inhuman and SHE keeps him from being impulsive and naive.
*One thing to note. The reason I wish to keep her alive (even when she betrays us at the Landsmeet) is not just because I believe her necessary for Ferelden's future. I also believe that she had nothing to do with Cailan's death and (despite what she may seem) that she did love him. She does not deserve to lose her life because of her father. I believe she loves Ferelden however she does love her position more. One reason why I did not wish her to rule alone.
2.) Loghain abandoned good warriors on the battlefield, betrayed his king, and blamed innocent people for it. As a warrior this kind of treachery is the foulest. To not help a comrade DURING battle when you said you would is the same as killing them yourself. Then he has the gall to blame someone else. This not only shows he can't be trusted during war but he also has NO HONOR.
3.) Loghain is blinded by his fear and hatred of Orlais. Loghain allows Ferelden to be practically swallowed by the Blight because of his fear of Orlais. This shows a lack of objectivity and inability to prioritize threats. This shows he has BAD JUDGEMENT.
4.) Loghain becomes so self-centered to the point to where he believes he and he alone understands the true dangers that threaten Ferelden. He also believes that he cares about Ferelden more than everyone else. In his arrogance he goes to eliminate everyone who disagrees with him or would disagree with him such as Eamon, the Grey Wardens, and possibly the Couslands. He continues to spiral uncontrollably by betraying the values of his people as well as his own. Allying himself with a man who murdered a friend and his family out of jealousy and greed. Hiring assassins to murder people who did no wrong. Hiring an apostate blood mage to kill a man who, other than being a possible political rival, did nothing to warrant death. And lastly he allowed innocent beings to be sold as slaves to fund a civil war that he caused. This shows he is greatly IMBALANCED.
5.) All this shows one way or another that he has NO EMPATHY or COMPASSION.
It is for these reasons that I not only prevented his kingship but had him slain. He was too imbalanced to reason with, too angry to listen, no empathy to understand, and his word could no longer be trusted. Leaving him alive would risk civil war even were his daughter queen. It had been indicated that he would have allowed Anora murdered to discredit Eamon. If Ferelden was to survive the Blight, recover, and then flourish... then Loghain could not be allowed to be a part of it.
So there you have it. There's my reasoning. Thanks for reading!