Well, that depends on what you mean by a series.
I prefer books that can be read as standalone novels whether or not they’re part of a series. But I also enjoy a good series, as it’s an opportunity to see more of character I’ve enjoyed reading about.
Most of the romance series I read are about linked characters.
These are often siblings, friends, or professional colleagues, and each book will feature a different couple. I enjoy these series.
Some are about a common location e.g. Irene Hannon’s Hope Harbor series. While I enjoy these as standalone stories, I prefer a series with more of a link in terms of character.
Another kind of series is the linked series, where each book follows the same main character/s through different stories. These are often mysteries or thrillers, and may have individual stories as well as an overarching plot or problem to solve across the series.
If I Run/If I’m Found/If I Live by Terri Blackstock does this well, as the main character is on the run after being accursed of murder. Another series that does this overarching plot well is the Holly series by CC Warrens, which starts with Criss Cross.
I enjoy this kind of series, as long as each book has a complete plot with no cliffhanger ending.
Yes, it’s fine for there still to be questions, but the book must contain a complete story.
Mysteries are more likely to be individual stories where the whodunit is discovered at the end of each book, and there may or bey not be an overarching plot or problem to solve. I’ve yet to read a mystery that doesn’t say whodunit, so I enjoy these books because they can easily be read as
What I don’t enjoy are books that end with a cliffhanger.
I don’t like having to read the entire series to get the overall story. I especially don’t like it if the book promises to be a standalone story but isn’t. I feel ripped off if I don’t get a complete story (unless the book has been sold as a X-part serial … in which case, I expect the price to be cheaper as I’m not getting a full story.
I read one novel a few months ago which turned out to have a cliffhanger ending. The author released each book in quick succession as a marketing tactic, but I didn’t buy or read the second book. It’s not a marketing tactic I want to encourage.
Overall, I prefer standalone books that are part of a series.
How’s that for answering an either/or question?