I finished my Dune series reread a few days ago (I read every book except the Butlerian Jihad and Bene gesserit prequel books). In the end, my least favorite might be Children of Dune. I don't think its bad, but it has most of he stuff I hate about Frank Herbert's books more than any other one (its just missing the at times horrifying sexual stuff from GE, Heretics and Chapterhouse). CoD gets way too bogged down with the philosophy, or more specifically vision stuff. Page after page of nothing happening by Leto thinking/talking about his visions. The mini series was awesome, and this book isn't bad but its the weakest of FH's books.
I did like GE a bit more on my second reading. GE, heretics and Chaptrhouse mostly stopped wasting time in stupid vision stuff that screws up CoD. Instead, you have three books (mostle Heretics and CH, but a few sections of GE) that actually have very uncomfortable sex scenes that add nothing to the story and just make me wonder if Frank Herbert was becoming a bit of a pervert in his old age

I don't mean to say anything negative about him, its just that it really becomes an issue in some points. I think that Duncan/Murbella's first sex scene is probably the worse.
If I had to put the books in order of my favorite to least favorite (although I should point out that I enjoy them all), it would be
Dune
Dune Messiah
The House Trilogy
Winds/Paul of Dune
Hunters/Sandworms of Dune
God Emperor of Dune
Heretics of Dune
Chapterhouse Dune
Children of Dune
I also finished reading ST: TOS - Doctor's Orders. It was a pretty good story, even if the reason McCoy couldn't give command of the ship to Spock or scotty was not only extremely stupid, but probably went against what you could imply just from watching the original series.
Right now I'm reading a Star Wars book (
Kenobi) and I think my next Star Trek book will probably be the next part of The Fall (the public library is getting all of them as they come out, and I'm #1 on the waiting list for each one

). I do have Star Trek: Best Destiny to read (I got it for $1 at a book sale awhile ago) but it seems like whenever I think of reading it, I have a lot more stuff I want to read more.