Xenogears is sharky's favourite of the bunch and he actually loves the gameplay. I think it's all really subjective as far as which everyone will enjoy more. Xenosaga III is by far my favourite, followed by I. The story is best in Xenogears though, I think, and the world is best in Xenoblade. I actually don't like Xenoblade's gameplay much myself but it's still a very good game. I think the genral consensus though is that Xenosaga II is probably the worst of the lot by a good bit. Which is a shame because it gets so much better in the next entry.