Dune, eh? Good luck with it. I thought the first one was OK, but hated the second, so I stopped there.
Yeah, I've heard that the series was not very good after the first book, so I'm only going to read the first book in the series and leave it at that.
No no no no no. While it's true that the original is pretty much the best in the series, there's some pretty interesting ideas explored in most of the sequels. "God Emperor of Dune" is one of my favorite books just because of how fucking odd it is.
You can definitely stop after that one, though. :P