(Note: contains no spoilers, but does include my opinion on the quality of Fallout 3's ending. Also I wrote this a few days ago and have since gotten over it and started a new character up.)
Games with bad endings have always baffled me. Much like a novel with a bad ending, I don�t see why someone would pour so much work into the bulk of a piece of work and then botch the ending. Obviously, not all endings can be simply called �botched� - some may feel right to the author but not take off with the general public. This happens a lot with movies, and we end up with director�s cuts.
With games, it seems that most developers just don�t care about the ending. It may be a bit harsh to come out and say it like that, but I honestly can�t see the reason so many games have such terrible endings aside from simply a complete and total lack of effort. I don�t know if it�s because it�s at the end of the game, where budget or time constraint is most likely running the thinnest; or perhaps (although doubtful) it�s that once the player is done with the game their enjoyment doesn�t matter anymore to the developers, so as little time as possible is spent working on the ending. Or possibly that gaming is such an obscure, new form of entertainment that we simply haven�t found a good way to end a gaming experience, especially when it�s a good game. After all, in movies and books, having closure is good - but in games we often do not want the experience to end, which could feasibly impact our otherwise unbiased opinion.
In either case, I think having a good ending to a game is pivotal. Games with bad endings - even ones that I thoroughly enjoyed the entire way through - will leave a bad lasting impression on me, to the point of ceasing my recommendations of the game. This happened to me with STALKER, a game I enjoyed a surprising amount while playing, but the ending was so hideously insulting that I could do nothing but go into long rants about the game after beating it. It was so bad that I started picking on faults that I would have let go otherwise.
Fallout 3 has just done the same thing to me, and as a much more �high brow� game it really surprised and disappointed me. Whereas before completing the game�s main quest I was actually anticipating finishing and starting a brand new character, now after having finished it I don�t really have the initiative to go and actually do it. I�m not sure if this actually matters or not in the grand scheme of things as it�s a single player game, although it certainly must have some kind of effect. Something about Morrowind made me play that game on and off for almost a year, and I would pretty consistently bore my friends with new tales from �that FPS RPG with crappy combat�. Unfortunately, I don�t think I�ll be pestering them to such an extent with Fallout 3, although it almost has the potential to be there - although the game�s longevity is mostly to do with off-topic items (such as dungeon repitition, something much improved in Fallout 3 if you compare it to Oblivion), the ending remains the primary reason I�m not back in Vault 101 right now playing with facial hair options. In any case, I�ll definitely be looking forward to any Fallout 3 mods, expansion packs or sequels.