The Cupcakes ending was a thing of beauty to behold! First it started out with the child talking smack to Shepard, which got my blood boiling until she hacked into the Citadel VI system and reprogrammed her "This is my favorite store on the Citadel" line to broadcast everywhere in the known galaxy, causing mass panic and chaos in the Reaper forces. INGENIOUS! She didn't even need to blow up the Citadel or the Mass Relays either. Once the battle was all said and done, Shepard was given a seat on the Council, and a Big Ben-sized statue on every race's homeworld with the words "I'm Commander Shepard, and this is my favorite homeworld in the galaxy!" inscribed in the plaque. Finally, the big moment arrived: CAPTAIN Shepard! That's right, the girl who saved the galaxy thrice before finally got her due promotion. In the after party, she, along with an unmasked (and clearly visible) Tali and a re-built Legion reinvent the Lazarus vector to bring back Mordin, and the four of them tour the galaxy in the broken husk of Harbringer, making pit stops to punch random reporters.
It truly was the most magical moment in gaming.