I wasn't a huge fan of X myself, but absolutely loved 1-3. I played through 1 multiple times in a row, doing all of the side quests each time. The plot turns are numerous and really keep the story moving. Not sure which I enjoy more between that and 2, which also had some fantastic story telling. 3 did an excellent job tying them together, and had my wife crying at multiple points in the story! X has a TON of in depth side stuff, but I felt very underwhelmed by the main story.

As far as what they're like, if you're familiar with Xenogears and Xenosaga, they're by the same guy. I haven't played those, but I can't recommend the Xenoblade series enough!