I liked the ending of Fallout 3. It's people who can't appreciate good narrative who balk at it.
The Lone Wanderer grows up in a vault, learning the virtues of compassion, mercy, and justice in a world where these have been all but abandoned. In the end, he sacrifices himself to purify the tainted waters of the Earth. Martyrdom to cleanse the world of man's evil deeds. Sound like somebody you may have heard of? That's right, the Lone Wanderer is Jesus.
It would have been a great story if I were watching a movie or reading a book. But as a game narrative, it just railroads you. You have few meaningful choices to make during its entirety.
The martyrdom at the end wasn't necessary. It was forced on you for "dramatic impact". Anyone that played the game prior to Broken Steel knows how screwed up it was. You were likely to have Fawkes, the conscripted ghoul companion, or a robot companion with you, all who could safely enter the chamber and input the code without dying. Instead, when asked, each told you it was your destiny. The game was forcing you to die, regardless of the fact that Fawkes had done essentially the exact same favor for you just a little while prior in retrieving the GECK.
And if you chose to draw straws with Lyons to enter the chamber, like any normal two people would, and she ends up going into the chamber, the game calls you a selfish monster. And even with Broken Steel, where they fixed the companion issue, if you use one them to enter the code, like Fawkes, the game ending still berates you with "but the son did not learn the lesson of sacrifice from his father". [censored] you. I'm not martyring myself for your dramatic purposes no matter how much you want it game!
Bethesda even admits that they started writing the story with the ending scene in mind, which explains why everything went wrong with the story. In an open world game supposedly built on players' choices and consequences, you can't put a single definitive ending in place and force everything towards that one inevitable ending. Bethesda left no breathing room.
Anyone that has played a pen and paper RPG with a DM or GM more concerned with telling their grand epic story than creating and guiding players in their own narrative knows what I am talking about.
I'm finished. Like I said, in any other medium, the story would have been great, but it wasn't one suited for an interactive medium. And how about this for a shocker? I don't want to be Jesus.