The original quartet is epic, Xenocide and Children of the Mind get a little bit off the cuff, but I really like them. Even the first few in the "Shadow" series were ok, but then quality dropped off. Now there are dozens of books set in the universe.

There really is one for every occasion.

The fairly magic particles in Xenocide are based on Mormon theology, so if that's not compelling to you, the exposition of same in CotM is going to be pretty boring.

The moral philosophy espoused throughout the series, namely, the primacy of intention, is heavily influenced by OSC's Mormonism. At least, that's what I remember reading in an interview. I am by no means an expert on Mormonism, so I would defer to anyone better informed than I on that matter.

The aiua? Do you think so? I thought they were just a science fiction way of talking about the soul. Mormons do believe in souls, I'll grant, but they hardly own the concept.

That's really compelling to me as a Mormon. I'll have to go back and read them and look for the parallels.

I did quite like Ender's Shadow.

The rest of the Shadow books weren't as bad as Children of the Mind, but they did seems to just follow a formula.

I've found all of OSC's series to be like that. I don't care for his short stories, either. I've always thought his standalone books, though, were incredibly good. Treason being an example, and Home Body.