Possiblity of Aizen being the good one.
If you don't read bleach manga/ or you wanna watch the anime then gtfo
My theory is what if Aizen's roll was like Itachi in naruto
I mean aizen had every thing in his hand, he had every chance to get what he wants..
he had chance to kill all the captains, he didn't
he had chance to kill ichigo, he didn't, but made him more powerful by purging the cleaner
he had chance to take out all ichigo's city in same time of him reaching there
but he didn't
if you noticed he only killed 2 main people in all his time
the blind captain, and gin
the blind captain was already planing to take revenge on soul souity for that he killed him
gin was not even bothered by any thing execpt to take revenge on aizen, therefore aizen removed him
he wanted to kill the soul king, maybe after those years of searching about how to get the keys he became to know that the soulking might be the evil one, for 2 reasons i think they are true, First one his form looks like Aizen in his hollow form ...*hollow* form, Second he might have gave the birth to hollows.
and about him stabbing that girl, if he really wanted to kill her he would one shotted her simply, from first time, But he didn't , its not also possible for him to miss a killing blow...
And ONe more point
On last arc Quincy's army came, started a war, all just as the captien of quincy said, * i came here to talk with Aizen to join our force* but he said NO
not that also, aizen stopped the quincy leader from killing ichigo and made him and his full army to retreat to back to his country even tho he was getting ready to fight the zero squad, if aizen was evil he would not have gave a single shit about what was happening..