>>7156294282 is the better game in an overall failure of a trilogy, so that leaves me feeling like 2 was the best experience, followed by 1 because back in 1 you still have the illusion, and still a glimpse, into how the trilogy was shaping up before it immediately ruins itself.
3 is just frustrating on every level. It's a terrible sequel to the way ME2 pivots the trilogy and outright ignores most of its "plot", and it's still a stinky sequel to ME1 in that we already knew the Reapers ruined every civilization of all time, who tried everything against them, but still choose to make the whole plot about "saving Earth" for some stupid reason that makes no sense.