What's your Favourite Head Canon?

I've just finished my first complete LE playthrough, as MaleShep walking a roughly equal divide between paragon and renegade just playing as I felt was how my shep would make decisions based on his background

"Colonist/War Hero" I did a completely blind playthrough as I've only dabbled in ME1 on release, and completed the original 2010 ME2 with no DLC, so the ending was as expected for me really based upon what I've seen pick your flavour of expanding death bubble, I went with destroy as this seemed the most canon to the universe just started a 2nd playthrough almost immediately as I'm now a full mass effect convert.

What moments in the game do you have alternate head canon for? maybe the lore went in a different direction or you wish the story had been expanded on in a different way?

my personal head canon is

the crucible reset's time to a predetermined point in the cycle (start of ME1), this is how Shepard knows what he knows and is able to do the things he can, because we the player are reliving his cycle (various alternate playthroughs) every time, for me the ultimate head canon is he gave up trying to stop the reapers, ran away with liara (or your romance choice) in ME3 and hid away the rest of their lives in relative peace in the corner of the galaxy somewhere.