I picked the MEHEM after waiting for over a year for the ending to be fixed and even with the extended cut the ending was still no closer to what i'd expect with maxed out assets and such, I picked no star child and no space magic thanks to mods ME3 got a better ending 
I just hated that you had no choice its was pick a colour and deal with it no chance to see if the geth and quarians could actually carry on rebuilding together ect, star childs BS about organics and synthetics just killing each other I would have loved to ram the unification of geth/quarians down his throat lol. The fact the ending created a ton of plot holes and removed all player choice was a major downer IMHO.
I like an ending to reflect what i've done in game if its a story driven RPD different endings that reflect actions and choices is a most and having vastly different out comes is what makes these games worth replaying.
Maybe this is a bad idea, but I'd like to point out that A) the Catalyst has eons, EONS, EONS of experience with the issue (I don't think some special snowflake human meathead is going to solve this issue), and B, he specifically says that in the past humans and synthetics have come to an accord, but the end result was conflict. There was no plot hole (as far as this point is concerned, and really for most of the plot hole arguments). But I digress.
As far as vastly different outcomes, the only way to do that in a way that actually allows them to maintain universe continuity is for the choices to be very insignificant things. There's a reason we aren't going back to Orzamar. There's a reason why they forcibly broke up the circles (in a manner of speaking) in DA ][ (that reason being, in DA:O one of the boon's was to free the circle in Ferelden). It's not possible to show these kinds of things in such detail.
The only other game in recent history I know of that does this kind of thing (outside of ME, which was regularly criticized for a lack of visible consequence), The Witcher, has one spectacular example, but deals with the endings by jumping to a new area each game (something DA does as well). it's just not a hugely feasible concept for a game to have pyramids of unique, divergent content.