Without getting too personal, I'll just say it's the characters first and the universe second. At first, I was in it because I was a huge Gears fan
Xenogears is what brought me to Xenosaga as well. After finishing Xenogears, and seeing "Xenogears: Episode V"
at the end of the credits, I immediately started searching for more info as to why it was called Episode V. I soon learned about Xenosaga and decided to import it without looking up all that much info about it, actually (iirc I checked out the official XSI site and that's about it)
. At that time XSII had just been released, so I imported both XSI and XSII together.
I soon found out Xenosaga had quite a different feel to it than Xenogears. It was still great, but never managed to wow me in the same way Xenogears did. One possible reason is because, as I've said before, in Xenogears I love both the subplots and the main story arc. But as for Xenosaga, well;
Now to finally get to the answer to the thread's question;
what do I love about Xenosaga? The subplots; URTV arc (pretty much what kept me hooked throughout the 3 episodes the most of all)
, Kevin/Shion arc, Jin-Margulis rivalry arc, Cherenkov's arc, Virgil/Febronia arc, Ziggy's past & Voyager arc,...
However, the main story arc about Wilhelm's grand scheme and the whole Yeshua/Mary Magdalene thing? Sorry, Xenosaga, but you completely failed to catch my interest with the main story arc. That's basically why my love for Xenogears is still much
because Xenosaga's main story arc didn't do anything for me.
So yes, in short, the subplots with its many wonderful characters is what I love about Xenosaga.