I liked Harry Potter series better than Lord of the Rings because I can put up with just so many extended fighthing scenes before I bail. Granted, the movie has affected my perception of the print series especially since I read the books 20 or more years (or so it seems) before I watched the movies.
"You" mentioned series; fantasy and sci/fi. I prefer fantasy and the vampire/werewolf type rather than fairy tale types. Therefore some of MY favorite series are:
Dresden Files by Jim Butcher
Patricia Briggs-Mercy series
Both of Ilona Andrews' series
There is a sci/fi series I like but I hesitate to mention it because I cannot remember the name, characters or author-but-it is about this female space ship captain or maybe she is a navigator and her trials and travels