I like to read standalone novels but I also like to read series.
Growing up, I adored the Babysitters' Club and Sweet Valley High (there's doing to be a new series for the twins with them in their late 20's). The Anne books. Nancy Drew. I loved the Chronicles of Narnia and Lord of the Rings (although technically, LotR is just one really long book).
Since then, I've read many more series, including Harry Potter. Currently, I'm on book 3 of the Sookie books. I really liked the first book. The second is good but not as good as the first. So far, book 3 seems even more downhill.
Will I continue to read them? Yes. But why have they started to turn south on me? That's hard to say.
I've been thinking about series a lot lately as I'm working hard to finish up Champion of Valor, Book III in the Kingdom of Arnhem series. I want to tie up all the loose ends, develop the characters from the previous books further even while I balance introducing new characters and races. It's a balancing act.
I think with series, it's important to continually build. You have to have character growth in each book and throughout the series. Each book should be separate and yet when read together, there should be something more. There should be an overlying arch to the books in a series.
Do you like to read series? Why or why not? What's your favorite series? Mine is probably Harry Potter. Or Outlander.