My first and main Inquisitor, Maelyn Trevelyan.
Her character is defined in considerable detail in
this post, and her story is told in
this thread. Later replays didn't change anything except that she didn't have an LI any more, and that she didn't kill Alexius. Here are pictures and a summary of her story:
(eh...is there a way to make these pictures smaller?)


Summary:
Maelyn is a mage with a Libertarian streak. She wasn't a rebel, but she always wanted to get away from the Chantry and the Templars, out from under the eyes of an institution and ideology she dislikes. That she ended up leading an organization powered by faith, and herself being regarded as a religious figure, was a matter of considerable annoyance for her, and despite the need to prevent Corypheus' dark future she was somewhat curious about what he wanted to achieve and how. Not that she wanted to take his place, but in her opinion, there's one thing of which you can never have enough - autonomy - and her present situation indicated all too well that hers was severely lacking.
Her decisions during the lifetime of the Inquisition were aimed - apart from stopping Corypheus - at increasing the power of her organization, so that it could stand on its own after the primary task was done. She worked with Leliana to gain secret knowledge from all over Thedas, and made her spy network her main source of power. Of course she also allied with the mages, and she supported Celene in Orlais because she saw Gaspard's expansionist ambitions as a future threat to her organization. She supported Cassandra as the new Divine because while she disliked the Chantry, she considered further instability detrimental for Thedas in the face of the qunari threat, and saw her as the most balanced candidate. Leliana had admirable goals, but she was a radical, and radicals as rulers are risky. Vivienne wanted the Circles back and increase the Chantry's institutional power, which Maelyn would never support.
The events in Frostback Basin increased her dislike of the Chantry, while also giving the new Inquisition a foundation that appealed more to her. She didn't believe in gods, she had said to Corypheus, and she considered both aspects of that undesirable: the desire to acquire god-like powers only to reshape the lives of people, and the desire of people to raise up some entity as a god, ready to let their lives reshaped according to another's will, or the religious elite's will. She did desire such power for herself, but only for the purpose of increasing her own autonomy, and she once told Cassandra to kill her if she ever came to enjoy the reverence of people for that illusionary "Herald of Andraste" they saw in her. She'd like to see people leave that immature dependence behind them, but was aware of the fact that most likely, she wouldn't see this in her lifetime.
When the Inquisition was challenged by Orlais and Ferelden, she was undecided at first. She did have imperial ambitions, but still the Inquisition was powered at least in part by faith, and she disliked that as much as when the Inquisition was founded. So the decision to disband the Inquisition, rather than have it serve the Chantry, came easily to her in the end, and since secret knowledge had always been her main source of power, stepping away into obscurity suited her new goals and personal preferences both. Unsurprisingly however, she was greatly annoyed by losing the Mark. She would've given the other hand in order to keep it, and suspected that Solas could've taught her to control it but chose instead to remove a possible future threat to his plans. So not only does she have a personal grievance with him, but he also represents what she's always fought against. She considers his goal - the sundering of the Veil - desirable, but not at the price of destroying the world as we know it.
Decision summary:
-Allied with the mages
-Reunited Celene and Briala
-Allied with the Wardens
-Left Stround in the Fade
-Saved the Chargers (she dislikes the Qun a great deal)
-Made Cole more human. She has no preference, but it seemed like what he wanted.
-Did not interfere with how Leliana did her job, causing her to remain pragmatic and hard.
-Made Rainier join the Wardens in truth.
-Told Dorian to let his father speak, which resulted in a tentative peace between them.
-Kept Cullen off Lyrium.
-Let Leliana steal the contract on House Montilyet from the House of Repose.
-Did not influence Cassandra's decision about the Seekers.
-In her judgments, she was lenient and tended to recruit the accused as agents, but she killed Erimond.
-Accepted the deal with the Sentinels at the temple of Mythal.
-She did not drink from the Well of Sorrows because while she desired the knowledge greatly, her autonomy was one of very few things she wouldn't give for it.
-Disbanded the Inquisition
How she regarded her Inner Circle:
-Dorian: became a close friend. She would've liked more. Very much. It was not to be...
-Solas: a kindred spirit - or so she thought until he revealed his plans. Still, she doesn't view this as a betrayal. Solas must be stopped, but she hopes he can be convinced of another path.
-Sera: Not really her type. Much too vulgar, for one, if somewhat likeable and unexpectedly funny at times.
-Iron Bull: She didn't get really close to him, though she trusts him now.
-Vivienne: Didn't trust her in the least, but kept appearances up. She suspects it's the same for Vivienne.
-Cassandra: An unexpected friendship. They had quite a few friendly debates about faith, which engendered mutual respect in spite of their differences.
-Blackwall: Not her type.
-Varric: She didn't really get close to him, but he was a trusted friend who could always make light of....well, sh*t.
-Cole: She liked him as well for who he was as for what he was, and valued him for insights into the spirit world. How he regarded her she was never that sure of, but he did stay, that should count for something.