I enjoyed all four books in the Hyperion-Endymion series. That was the first of a number of SF series I read, so it has a special place for me. I read on into the Endymion books because I was so intrigued by the evil AI schemes and the anti-Catholic themes.
I've read a number of SF series and here's how I'd compare them.
After Simmons (his later ones Illium and Olympos aren't as good, but if you're a sucker for SF you might check them out; mind you, his Carrion Comfort is much better), I read Peter F. Hamilton's long Reality Dysfunction series. That series has great action, more scientific jargon, and a lot of world-building. Hamilton is better at describing science and technology than is Simmons--without going full science-textbook on you, like Greg Egan.
Next, I read David Zindell's Neverness series and that has another special place for me, despite its flaws. It's a very philosophical and spiritual take on science fiction. There are some wonderful ideas and descriptions in there and if you're into spirituality without the religion, or into Eastern philosophy, you might want to check out Zindell. I didn't get all the way through his fantasy series, because it was a little too close to the Neverness story, which is what Zindell says he intended.
I also read Gene Wolfe's 12 book Sun series. What a whopping complexity that series is, but all in all I'd say reading it was worth it. Jack Vance's Dying Earth books are great as well--and much funnier than Wolfe's Sun books.
Where does Simmons's series fit into this mosaic? Simmons brings in a literary perspective--not so much in his writing style but in his allusions to other authors. This can get a little pretentious, as far as I'm concerned, but what I like most about the Hyperion Cantos is its elaborate plot and the coolness of the characters' schemes and of Simmons's religious ideas. It's not great on action or on technoscientific descriptions, and Zindell's series is much deeper with respect to the philosophy and spirituality. Wolfe's series, by contrast, has the most elaborate plot and Wolfe's writing quality is probably the best. Zindell is great too, although his failing is that he badly overuses certain cheesy words and phrases, like "light of the eyes." Also, Zindell can get a little sentimental, but he makes up for it.
I started reading Dune and Foundation, but for some reason I didn't get far. In fact, I'm having a hard time now finding a novel I can enjoy. This is why I hesitate to reread those treasured series, in case I spot more problems with them than I did on first reading (although I doubt that would be possible with respect to Wolfe).
