Destroy will never work for me, especially after helping the geth attain free will- essentially: sentience.
I think, therefore: I am. Personally, I found the star-child's reasoning so flawed, especially in combination with a lack of reaction from Shepard to these flaws, that I completely lost any immersion during the ending. And I don't believe in any IT at all- just in a rushed ending with terrible writing/not enough thought put in.
So working within the boundaries of this, I chose synthesis. Although in a way, I do believe that this would take away free will because it's in our nature to fight as sentient, territory-driven creatures.. I took into account again: bad writing. There was no real good answer, in my opinion. I really don't have any right to rewrite someone's DNA, but within the boundaries of the game, I think this was meant to be the most "paragon" answer.
Control was my next best option, but I can't have any faith that Shepard will not eventually begin thinking "pragmatically" without accounting for "human nature" and emotion. Shepard is no god and in my eyes should not start thinking like he/she is one- that despite the constant warnings to TIM that suddenly, at the flip of a switch, he/she changes his/her mind when it applies to themselves. It seems like a temporary solution to me. But that's a lot of speculation with no real answers.
Anyhow. In the end, I chose headcanon. MEHEM was a little choppy for me, honestly. But I know that's the one that fits the best since it can be "installed". There was another video that I saw that I actually found to flow very well.. And out of all of that, I liked that one if nothing else.

Either way, the only ending for me is my own.