I would say the original Breath of Fire, but it turns out that I got the bad ending (even though there's absolutely 0 indication that it was the bad ending, and the other ending is much better), so I don't think that's fair to say.

So... I honestly don't really know. I don't usually branch out much beyond Squeenix and Bethesda games when it comes to RPGs, and theirs are usually rather good, if not FANTASTIC (Like Final Fantasy XIII-2 ). If I was forced to choose, I would say the Pokemon games, as they have 0 specialness to their endings at all. You win, become the best in the region, and that's it. Exactly what you expect will happen, and nothing more. No necessarily bad endings, but disappointing.