If I have not read all the books in the series -- I have not included it on this list, with this exception: if there is an ongoing series -- and I have read all but one or two, and I am continuing to read the series, it HAS been included. This way, I don't have to re-do this list every couple of months!
This being said, there are sometimes "stand-alone" novels -- and while I have tried to include them all -- I freely admit that I may have missed some.
Incidentally, sequels written after the author's death by other writers are typically not included -- the major exception being the completion of the "Wheel of Time" series, as Brandon Sanderson was working from the notes of Robert Jordan.
I'm sure that I have missed some . . . stay tuned!