Beat the game. Uhhh alright, I'm not gonna defend the ending as such, but I will say I don't see what gets people so pissed of with it. Yeah it comes out of nowhere and yeah it appears to be a very weak and uninspiring copy of Deus Ex's ending choices, but it's not exactly a new low for the series. The Reaper invasion plot already didn't make much sense post-ME1 so it doesn't bother me that the resolution to it is a nonsensical ass-pull. It's pretentious melodramatic nonsense, but pretentious melodramatic nonsense is exactly what Mass Effect has been from the start.
Having said that, I chose the "Control" ending (apparently I didn't have enough war points for the other endings - I was wondering what the hell I was gathering all those points for), and I don't get what the hell was happening in the cinematic. Shepard merges with the Citadel or something, okay, it's just the Helios ending from DX. But then a blue shockwave fires throughout the galaxy, which is doing Shepard's will or something, and makes all the Reapers fuck off. Okay, fair enough. But then the shockwave blows up all the mass effect relays and destroys the Normandy? Why would it do that? Isn't Shepard meant to be controlling the wave? Maybe she's just as fed up with the Normandy and its crew as I am at this point. Makes even less sense since the subsequent ending slide shows her sending the Reapers to rebuild the relays.
Whatever, maybe it's just because people hyped it up to be the worst thing of all time, but the ending wasn't that bad. It was bad, but only by the usual standards of Mass Effect. Looking over all the endings in the wiki and the one I would have wanted to do was destroy the Reapers at minimal cost and with Shepard surviving, but I had the variant where the resulting blast would have killed everyone everywhere in the multiverse or something.