Books that aren't a standalone story are a pet peeve of mine. If the publisher is deceptive enough to not indicate that it's a planned series in the synopsis or on the cover and I read the entire book only to find out that it's a set up, I would be a little ragey.

Same as Portable Magic, I can't stand when a book is merely a setup for the next installment. It's usually a sure way for me not even consider the author again.

I knew when I started reading that it was a series, but you also have series in which you can read the books as a standalone. I usually prefer those. The thing is that what is referred to in the synopsis only happens at the end of the stories, so it really carries over for the biggest part to the next book (I assume, since I haven't read it yet).