Truth be told I really don't know which Voyager books are worth reading. When I had a look on Amazon a lot of the premises of the early ones just did not sound that interesting.
There is also this issue that a lot of reviewers tend to hype up the books, I doubt that almost each and any one of then of them is a must read for a Star Trek fan.
I’ve read all the Voyager novels, and the pre-Endgame ones are good. The only major issue is #11, “The Garden”, which has like 5 chapters and each chapter is about 60 pages in length.