"True" endings seem to be a bit tricky. On the one hand, having a "true" ending can be a way to create continuity between games, or to show the player several different facets of the story through other endings and then pull them all together in a nice big reveal. On the other, a single "true" (read: "best") ending can take away a lot of the fun of having multiple non-losing endings in the first place.
Well, I like using examples, and I might as well cut to the chase here - so take "Fantasia: Requiem of the Abyss," which I guess would be an appropriate example for this topic.

I think it was fairly obvious that the author considered the ending in which Valen, the heroine, ends up with Cain, her demon bodyguard, as the "true" ending and treated it accordingly. As a player, and one who enjoyed the game overall, I thought this was a poor design decision for a couple of different reasons.
First, the game has a dating-sim aspect to it. Even though there's a strong over-arching plot, it moves along without much input from the player. The choices you make and the endings you get are heavily slanted towards "obtaining" one or another of the characters. And since the whole point of having more than one obtainable character in a game like this is that people find different "types" attractive, telling players that one of them is the "real" goal is kind of pointless -
de gustibus non est disputandum. I'm not really into the "emo demon" type, so I said "to heck with this 'true' ending, I'm going after Prince Nazim instead" and the story I got as a result was indeed very cute and made me go "aww" and I enjoyed it, but it was irritating that the game seemed to be pushing me away from all the perfectly good (from my perspective) alternative endings and towards Cain's. It just doesn't matter which is the "true" ending when they're all equivalent to the player.
Which brings me to the second point. The player's instinct that all endings are equally good (in this kind of game) doesn't mesh well with using a "true" ending as a hook for a sequel. From playing the demo for the next game in the series, I'm pretty sure that the sequel assumes Valen and Cain ended up together. But because that wasn't my experience when I played the game, it felt odd that the game was assuming that, and it damaged the feeling of the series as a coherent whole. Why give the player a choice of endings when it's just going to be assumed that they got the "true" one?
In the end, it seemed like the author had two different goals in mind for the story - on the one hand, telling an epic love story between two particular characters, and on the other, giving players a lot of different character endings to choose from. I'm just not sure that those two goals can coexist very comfortably; if the game is meant to be really about two main characters, it should stick to being about them, but if it's meant to offer the player the choice of focusing on one of several different characters, it shouldn't make all but one choice marginal and meaningless in the sequel. Having a "true" ending would work better in another kind of game - say, a mystery game, where the true ending is the one where you solve the mystery completely, and other endings reveal alternate views of the story or more information about the characters.
...Anyway, since this turned out to be more of a critique, don't take it to mean that I thought the game was bad, though! As I said, I enjoyed playing it, but like pretty much every game, it had room for improvement, and that was one thing that jumped out at me.
